home Endocrinology What kind of disease is fever dangerous? Fever is high body temperature. Causes and treatment of fever. What can you do

What kind of disease is fever dangerous? Fever is high body temperature. Causes and treatment of fever. What can you do

Increased body temperature that is not caused by changes in the hypothalamus is usually called hyperthermia. Many patients use the term “fever” very loosely, often implying a feeling of being warm, cold, or sweating without actually taking their temperature.

Symptoms are primarily due to the condition causing the fever, although the fever itself may cause discomfort.

Pathogenesis of fever

The goal of the body's thermoregulation system is normally to ensure that the actual internal body temperature remains at a set level of about 37 °C (with daily fluctuations). In contrast to passive hyperthermia, during fever the mechanisms of thermoregulation are preserved and when exposed to the pyrogenic factor, the set point of temperature homeostasis increases. In this regard, thermoregulation mechanisms begin to maintain an increased temperature (green line). Clinically, this becomes noticeable during an increase in body temperature. Since the actual body temperature does not correspond to the increased set point, the body reduces heat loss due to decreased cutaneous blood flow, resulting in cooling of the skin (cold sensation). In addition, heat production is also increased due to shaking (tremor). This continues until the actual temperature level (red line) approaches the new set point (plateau). When the set point for temperature homeostasis decreases, body temperature drops because the actual level is now too high. Accordingly, the skin bleeds, the person feels hot and sweats profusely.

Fever is especially characteristic of infections as a manifestation of the acute phase reaction, in which pyrogens are the cause of the change in the set point. Exogenous pyrogens are structural elements of the pathogen, and the most active of them are lipopolysaccharide complexes (endotoxins) of gram-negative bacteria. These pathogens, or pyrogens, are opsonized and phagocytosed by macrophages, such as Kupffer cells in the liver. Macrophages secrete many cytokines, including endogenous pyrogenic interleukin, interferon, tumor necrosis factors TNF-α (cachectin) and TNF-β (lymphotoxin), macrophage inflammatory protein MIP-1 and many others. These cytokines (with a molecular weight of approximately 15-30 kDa) are thought to reach the circumventricular regions of the brain, which do not have a blood-brain barrier. Cytokines can therefore induce a temperature response in these organs or in the nearby preoptic zone and vascular organ of the lamina terminalis via prostaglandin PGE2. In this case, antipyretic drugs (antipyretics) are effective.

For example, acetylsalicylic acid inhibits the enzymes that convert arachidonic acid to PGE2.

Considering that after intravenous injection of lipopolysaccharides, the above-mentioned cytokines are released only 30 minutes after the onset of fever, and with subdiaphragmatic vagotomy their release is delayed, one should think that exogenous pyrogens activate the preoptic region and the vascular organ of the terminal lamina also through afferent fibers from the abdominal cavity. It is possible that the signaling substances secreted by the Kupffer cells of the liver activate the afferent fibers of the vagus nerve closest to them, which transmit the pyrogenic signal through the solitary nucleus to groups of noradrenergic neurons of types A1 and A2. They, in turn, transmit a signal from the ventricular noradrenergic pathway to the thermoregulatory neurons of the preoptic area and the vascular organ of the lamina terminalis. Norepinephrine released there causes the formation of PGE2, and through it, fever. This usually causes the release of ADH (V 1 -receptor effect), α-melanocyte-stimulating hormone (α-MSH) and corticotropin-releasing hormone (CRH; corticoliberin), which prevent the development of fever through negative feedback due to the release of endogenous antipyretics.

Due to an increase in body temperature, heart rate increases (by 8-12 beats per minute per degree) and energy metabolism increases, resulting in fatigue, aching joints and headaches, and the phase of slow wave sleep (which performs a restorative function for the brain) is prolonged. , and also, under certain circumstances, disturbances of consciousness, sensory disturbances (delirium febrile) and convulsions occur. The role of fever is to counteract infection. Elevated temperature inhibits the replication of some pathogens and kills others. In addition, the plasma concentration of metals necessary for bacterial reproduction, such as iron, zinc and copper, decreases. In addition, cells affected by viruses are destroyed, which slows down the replication of viruses. Therefore, exogenous antipyretics should only be used if the fever is accompanied by seizures (usually in infants and young children) or is so high (> 39°C) that seizures are feared.

During a 24-hour period, body temperature varies from the lowest levels in the early morning to the highest in the late afternoon. The maximum change is approximately 0.6 °C.

Body temperature is determined by the balance between heat production by tissues, especially the liver and muscles, and heat loss in the periphery. Typically, the thermoregulatory center of the hypothalamus maintains core temperature between 37° and 38°C. Fever results from the hypothalamic control point being elevated, causing vasoconstriction and shunting blood away from the periphery to reduce heat loss; Sometimes shivering occurs, which increases heat production. These processes continue until the temperature of the blood washing the hypothalamus reaches a new point. Rebooting the hypothalamus point downward (for example, with antipyretic drugs) provokes heat loss through sweating and vasodilation. The ability to generate fever is reduced in certain patients (eg, alcoholics, very old people, very young people).

Pyrogens are those substances that cause fever. External pyrogens are ordinary microbes or their products. The best studied are lipopolysaccharides from gram-negative bacteria (commonly called endotoxins) and the Staphylococcus aureus toxin that causes toxic shock. External pyrogens usually cause fever by producing the release of endogenous pyrogens, which raise the hypothalamic point. Prostaglandin E 2 synthesis plays a critical role.

Consequences of fever. Although many patients worry that the fever itself can be harmful, the mild increases in temperature caused by most acute illnesses are well tolerated by healthy adults. However, excessive temperature rise (usually >41°C) can be dangerous. This increase is more typical of severe environmental hyperthermia, but sometimes results from exposure to illicit drugs (eg, cocaine, phencyclidine), anesthetics, or antipsychotics. At this temperature, protein denaturation occurs and inflammatory cytokines are released, which activate the inflammatory cascade. The result is cellular dysfunction, leading to malfunction and ultimately failure of most organs; the coagulation cascade is also activated, leading to disseminated intravascular coagulation.

Because fever can increase, with the basal metabolic rate at temperatures above 37°C increasing by approximately 10-12% for every 1°C, fever can produce physiological stress in adults with pre-existing cardiac or pulmonary insufficiency. Fever may also worsen mental status in patients with dementia.

Fever in healthy children can cause febrile seizures.

Causes of fever

Many disorders can cause fever. Broadly speaking, they are classified as:

infectious (most common);
neoplastic;
inflammatory (including rheumatic, non-rheumatic and drug-related).

The cause is acute (i.e., with a duration<4 дней) лихорадки у взрослых чаще всего инфекционная. Когда у пациентов появляется лихорадка из-за неинфекционной причины, лихорадка является почти всегда хронической или рецидивирующей. Кроме того, изолированная острая лихорадка у пациентов с установленными воспалительным или неопластическим процессами с большой вероятностью является инфекционной. У здоровых людей острая лихорадка вряд ли будет первоначальным проявлением хронического заболевания.

Infectious causes. Virtually all infectious diseases can cause fever. But in general, the most likely reasons are:

upper and lower respiratory tract infections;
gastrointestinal infections;
urinary tract infections;
skin infections.

Most acute respiratory and gastrointestinal infections are viral.

Certain patient and environmental factors also determine which causes are most likely.

Patient factors include health status, age, occupation, and risk factors (eg, hospitalization, recent invasive procedures, presence of intravenous or urinary catheters, use of mechanical ventilation).

External factors are those that place patients at high risk of contracting certain diseases - for example, through infectious contacts, local outbreaks, disease vectors (eg, mosquitoes, ticks), shared objects, food, water, or geographic location (eg, living in endemic area or recent travel there).

Some reasons based on these factors are predominant.

Two main questions are important in the initial assessment of acute fever:

Identify any local symptoms (eg headache, cough). These signs help narrow down the range of possible causes. The localizing sign may be part of the patient's chief complaint or be identified only by specific issues.
Determining whether the patient is seriously or chronically ill (especially if such an illness has not been identified). Many causes of fever in healthy people are self-limiting, and many (for viral infections) are difficult to diagnose accurately. Limiting tests to the severely or chronically ill may help avoid many expensive, unnecessary and often fruitless searches.

Story. The history of present illness should include the level and duration of fever and the method used to measure the temperature. Severe, shaking, teeth-chattering chills (not just a feeling of cold) suggest fever due to infection. Pain is an important clue to the possible cause of the disease; The patient should be asked about pain in the ears, head, neck, teeth, throat, chest, abdomen, side, rectum, muscles and joints.

Other local symptoms include nasal congestion and/or discharge, cough, diarrhea, and urinary symptoms (urinary frequency, incontinence, dysuria). The presence of the rash (including its nature, location, and timing of the rash's onset in relation to other features) and enlarged lymph nodes may aid in diagnosis. The patient's contacts must be identified.

Review of systems should exclude symptoms of chronic illness, including recurrent fevers, night sweats, and weight loss.

Previous medical history should include the following:

recent surgeries;
known medical conditions that predispose to infection (eg, HIV infection, diabetes, cancer, organ transplantation, sickle cell anemia, heart valve disease - especially if there is a prosthetic valve);
other known disorders that predispose to fever (eg, rheumatologic disorders, systemic lupus erythematosus, gout, sarcoidosis, hyperthyroidism, cancer).

Questions to ask about recent travel include inquiring about travel location, time since return, specific location (e.g., off-the-beaten-path, urban only), pre-travel vaccinations, and use of malaria preventive medications (if required) .

All patients should be asked about the possibility of exposure (eg, through suspicious food or water, insect bites, contact with animals, or unprotected sex).

Vaccination history, especially against hepatitis A and B and against organisms that cause meningitis, influenza, or pneumococcal disease, should also be reviewed.

The drug use history should include specific questions about the following:

drugs known to cause fever;
drugs that predispose to an increased risk of infection (eg, corticosteroids, anti-TNF drugs, chemotherapy and anti-rejection (eg, transplant) drugs, other immunosuppressants);
illegal use of injectable drugs (predisposing to endocarditis, hepatitis, septic pulmonary embolism and skin and soft tissue infections).

Physical examination. The physical examination begins with confirmation of fever. Fever is most accurately diagnosed by measuring rectal temperature.

Oral temperature is usually about 0.6°C lower and can be even lower for many reasons, such as recent ingestion of a cold drink, mouth breathing, hyperventilation, and inappropriate measurement time (mercury thermometers require up to several minutes) . Measuring tympanic membrane temperature with an infrared sensor is less accurate than rectal temperature. Monitoring skin temperature using temperature-sensitive crystals fused into plastic strips placed on the forehead is not productive for detecting increases in core temperature.

Other vital signs are assessed if tachypnea, tachycardia, or hypotension is present.

For patients with local symptoms, examination continues as described in this Guide. For patients with fever without local symptoms, a complete examination is necessary because clues to diagnosis may lie in any organ system.

The patient's general appearance should be taken into account, including any weakness, lethargy, confusion, cachexia, and depression.

The entire skin should be inspected for rash, especially petechial or hemorrhagic rash and any lesions or areas of erythema or blisters that suggest skin or soft tissue infection. The axillae and areas of the internal epicondyle of the humerus and groin should be examined for adenopathy. In hospitalized patients, the presence of any intravenous, internal (NGT), urinary catheters, and any other tubes inserted into the body should be noted. If the patient has recently had surgery, the surgical sites should be carefully examined.

When examining the head and neck, you need to pay attention to the following:

eardrums: inspection for infection;
sinuses (frontal and maxillary): percussion;
temporal arteries: palpation for tenderness;
nose: examination for congestion and discharge (clean or with pus);
eyes: examination for conjunctivitis or jaundice;
fundus: examination for Roth spots (suggesting infective endocarditis);
Oropharynx and gums: inspect for inflammation or ulceration (including any candidiasis that suggests decreased immunity);
neck: tilt to detect discomfort, stiffness, or both, indicating meningism, and palpate for adenopathy.

The lungs are examined for abnormal sounds or signs of consolidation, and the heart is listened for murmurs (suggesting possible endocarditis).

The abdomen is palpated for hepatosplenomegaly and tenderness (suggesting infection).

Percussion is performed along the lateral surfaces to identify pain in the kidney area (which suggests pyelonephritis). A pelvic examination is performed in women to check for cervical pathology or adnexal tenderness; A genital examination is performed on men to check for urination and local tenderness.

The rectum is inspected for tenderness and swelling, suggesting a perirectal abscess (which may be occult in immunocompromised patients).

All major joints are examined for swelling, erythema, and tenderness (suggesting joint infection or rheumatologic disorder). The hands and feet are examined for signs of endocarditis, including hemorrhages from splinters under the nails, painful erythematous subcutaneous nodules on the tips of the fingers (Osler's nodes), and nontender hemorrhagic spots on the soles of the feet (Janeway lesions).

Danger signals. The following phenomena should be given special attention:

change in mental state,
headache, neck stiffness, or both,
petechial rash,
hypotension,
dyspnea,
significant tachycardia or tachypnea,
temperature >40 °C or<35 °С,
recent travel to an area where malaria is endemic,
recent use of immunosuppressants.

Interpretation of results. The degree of fever is usually not related to the cause of the infection. The fever pattern, once thought to be significant, is not.

The likelihood of severe illness is considered. If severe illness is suspected, immediate and rapid testing and often hospitalization are necessary.

Danger signals strongly suggest severe impairment. Headache, neck stiffness, and a petechial, or purpuric, rash suggest meningitis. Tachycardia (below the normal increase usually seen with fever) and tachypnea, with or without hypotension or changes in mental status, suggest sepsis. Malaria should be suspected in patients who have recently been to an endemic area.

Decreased immunity, whether due to a known cause, the use of immunosuppressive drugs, or suspected by physical examination (eg, weight loss, oral candidiasis), is also a concern, as are other known chronic diseases, intravenous drug use, and heart murmurs.

The elderly, especially those living in nursing homes, are at particular risk.

Local findings identified by history or physical examination are assessed and interpreted. Other suggestive symptoms are generalized adenopathy and rash.

Generalized adenopathy may occur in older children and young adults with acute mononucleosis; usually accompanied by significant pharyngitis, malaise, and hepatosplenomegaly. Primary HIV infection or secondary syphilis should be suspected in patients with generalized adenopathy, sometimes accompanied by arthralgias, rash, or both. HIV infection develops 2–6 weeks after infection (although patients may not always report unprotected sex or other risk factors). Secondary syphilis is usually preceded by chancroid with systemic symptoms developing 4-10 weeks later.

Fever and rash have many reasons to be related to infection or drug use. Petechial, or purpuric, rashes should be given special attention; it suggests possible meningococcemia, Rocky Mountain spotted fever (especially if the palms or soles of the feet are affected), and, less commonly, certain viral infections (eg, dengue fever, hemorrhagic fevers). Other suggestive skin lesions include the classic erythema migrans of Lyme disease, lesions of Stevens-Johnson syndrome, and painful erythema of cellulitis and other bacterial soft tissue infections. The possibility of delayed hypersensitivity to the drug (even after long periods of use) should be taken into account.

If there are no localized findings, healthy individuals with an acute fever and only nonspecific symptoms (eg, malaise, generalized pain) are likely to have a self-limited viral illness unless there is a history of exposure (including new, unprotected sexual contact) to a vector. illness or exposure to an endemic area (including recent travel).

Drug-related fever (with or without rash) is a diagnosis of exclusion and often requires a decision to discontinue the drug. The difficulty is that if antibiotics are the cause, then the disease being treated may also cause the fever. Sometimes the clue is that fever and rash begin after clinical improvement in the infection and without worsening or reappearance of underlying symptoms (eg, a patient being treated for pneumonia reappears with fever without cough, shortness of breath, or hypoxia).

Carrying out analyzes. The analysis depends on whether there are local phenomena.

If there are local phenomena, tests are carried out in accordance with clinical hypotheses and symptoms. This applies to the following situations:

mononucleosis or HIV infection - serological analysis;
Rocky Mountain spotted fever - biopsy of skin lesions to confirm the diagnosis (serological analysis in the acute period is useless);
bacterial or fungal infection - blood cultures to diagnose possible bloodstream infections;
meningitis - immediate lumbar puncture and IV dexamethasone and antibiotics (CT scan of the head should be done before lumbar puncture if patients are at risk for cerebral herniation syndrome; IV dexamethasone and antibiotics should be given immediately after blood cultures are taken for culture and before CT head tomography);
specific tests are based on evidence of possible exposure (eg contacts, vectors or exposure to endemic areas): testing for these diseases, especially peripheral blood smear for malaria.

If there are no local findings in otherwise healthy patients and severe disease is not suspected, patients can usually be observed at home without testing. For most, symptoms disappear quickly; and the few who develop bothersome or localized symptoms should be re-examined and tested based on new findings.

If a patient is suspected of having a severe illness, but there are no local phenomena, tests are necessary. Patients with danger signs suggestive of sepsis require culture (urine and blood), chest x-ray, and evaluation of metabolic abnormalities with measurement of serum electrolytes, glucose, BUN, creatinine, lactate, and liver enzymes. Typically, a complete blood count is done, but the sensitivity and specificity for diagnosing a severe bacterial infection is low. However, the white blood cell count is prognostically important in immunocompromised patients (a low count may be associated with a poor prognosis).

Patients with significant abnormalities may need testing even if they do not have any local findings and do not appear severely ill. Because of the risk and devastating effects of endocarditis, intravenous drug users typically are admitted to the hospital for serial blood cultures and often echocardiography when febrile. Patients taking immunosuppressants require a complete blood count; if neutropenia is present, begin testing and obtain a chest x-ray, as well as cultures of blood, sputum, urine, stool, and any suspicious discharge from skin lesions.

Elderly patients with fever often require testing.

Treatment of fever

In certain cases, anti-infective therapy is prescribed; Empiric anti-infective therapy is required if severe infection is suspected.

Whether fever due to infection should be treated with antipyretics is controversial. Experimental evidence, but not clinical studies, suggests that fever increases host defenses.

Fever may need to be treated in certain patients at particular risk, including adults with heart or lung failure or dementia. Drugs that inhibit brain oxygenase are effective in reducing fever:

acetaminophen 650-1000 mg orally every 6 hours;
ibuprofen 400-600 mg orally every 6 hours

The daily dose of acetaminophen should not exceed 4 g to avoid toxicity; Patients should be asked not to concomitantly take non-prescription cold and flu products that contain acetaminophen. Other nonsteroidal anti-inflammatory drugs (eg, aspirin, naproxen) are also effective antipyretics. Salicylates should not be used to treat fever in children with viral illnesses because such use has been associated with Reye's syndrome.

If temperature >41°C, other body cooling measures (eg, cool water evaporative cooling, cooling blankets) should also be used.

Basics of Geriatrics

In frail older adults, the infection is less likely to cause a fever, and even if the infection raises the temperature, it may be lower than a normal fever. Likewise, other signs of inflammation, such as focal pain, may be less obvious. Often, a change in mental status or a decrease in daily functioning may be the only initial manifestations of pneumonia or a urinary tract infection.

Despite less severe illness, older people with fever are significantly more likely to develop severe bacterial illness compared with younger people. In younger adults, the cause is usually a respiratory or urinary tract infection, while in older adults, skin and soft tissue infections are among the main causes.

Focal phenomena are assessed as in younger patients. But unlike younger patients, older patients will likely require urinalysis, urine culture, and x-rays. Blood cultures should be done to rule out sepsis; if septicemia is suspected or vital signs are abnormal, patients should be hospitalized.

Fever- increase in body temperature over 37.2°C when measured in the armpit.

Fever is not a disease. Usually this is a sign of our body's fight against infection, or fever can occur as a symptom of a disease of a non-infectious nature (for example, cancer, myocardial infarction, autoimmune process). In addition, a febrile state can occur after taking medications such as contraceptives, antibiotics, and drugs for the treatment of arterial hypertension. Also, an increase in body temperature appears when the balance between the processes of heat production and heat transfer is disturbed in the normal state of the thermoregulation center (hypothalamus). This condition occurs during heat stroke.

Normal body temperature varies among people and depends on factors such as food, exercise, sleep and time of day. The highest temperature is reached around 6 pm and drops to its maximum around 3 am. The difference between morning and evening temperatures in healthy people does not exceed 0.6° C.

Depending on the cause of occurrence, infectious and non-infectious fever are distinguished.

According to the degree of increase, body temperature is:

subfebrile (37.2 - 37.9 °C);
febrile (38.0 – 38.9 °C);
high or pyretic (39.0 – 40.9 °C);
excessive or hyperpyretic (41 °C and above).

Low-grade fever does not require medical intervention; taking medications at temperatures up to 38.0 °C is recommended only in cases where there are subjective sensations that bring discomfort. In other cases, when the temperature rises above 38.0 °C, it is necessary to prescribe medications whose action is aimed at normalizing the temperature.

It is important to remember that fever can be a symptom not only of a cold, but also of many other serious diseases. Therefore, even if you managed to lower your temperature on your own at home, you still need to consult a doctor to find out the reason that led to the development of a febrile state.

Symptoms

Often a person does not feel a slight rise in temperature. However, when the temperature is above 38.0 °C, the clinic most often appears. There is redness of the skin (mainly the face) and increased sweating, due to which the person begins to worry about thirst. Fever may also be accompanied by a headache and a feeling of aching bones. There is an increase in breathing rate, a decrease in appetite, and confusion may occur. The person becomes lethargic, inactive, and drowsiness occurs.

In children, it is important to distinguish between “red” and “white” fevers, as there are different treatment approaches. In the first type, the child’s condition and behavior are slightly disturbed, the skin is pink, moist, hot, and the limbs are warm. This fever is more common in children and is more favorable.

The second type is characterized by a severe general condition of the child, behavior is disrupted, lethargy, moodiness, chills, pale and dry skin, acrocyanosis (bluish tint of lips and nails), increased pulse and blood pressure appear. Against this background, serious complications may appear, such as febrile convulsions and toxic encephalopathy, which require emergency medical attention.

Diagnostics

Measuring temperature makes it possible to identify a febrile state and is of great importance for diagnosis.

The measurement is made with a medical thermometer, which can be mercury or digital. Before the measurement, you should lower the mercury column of the thermometer to 35 - 35.5 ° C, check the condition of the armpit (it should be dry and without damage), and also evaluate the condition of the thermometer itself (its integrity, serviceability). After this, the thermometer is placed in the armpit for 10 minutes. In this case, the shoulder should fit snugly to the chest so that the armpit is closed. In weak patients, as well as in children, it is necessary to hold your hand during measurement. Normal body temperature when measured in the armpit is considered to be 36.4-37.2°C.

To measure rectal temperature, it is better to purchase a special thermometer for this purpose, the end of which will be rounded rather than sharp.

It is not always possible to measure rectal temperature; there are also contraindications. In case of intestinal disorders, stool retention, inflammatory processes in the rectum, the presence of hemorrhoids and anal fissures (during their exacerbation), this is contraindicated.

The patient's position is lying on his side with his knees brought to his chest. A layer of Vaseline is applied to the end of the thermometer to prevent trauma to the rectum. The end of the Vaseline-lubricated thermometer is inserted into the anus approximately 2.5 cm or until the measuring tip is completely covered. During the measurement, it is recommended not to move for 2-3 minutes. If a thermometer, when measuring rectal temperature, shows 37.1–37.9 ° C, this is a normal temperature.

Sometimes the temperature is measured in the mouth (orally). In this case, for safe measurements, it is better to use an electronic thermometer. You should not take your temperature orally if your mouth is damaged. You will also get distorted results if the person recently drank cold or hot drinks before the measurement. The thermometer is placed under the tongue, the mouth is closed, tightly squeezing the thermometer with the lips. Normal temperature under the tongue is 36.7 -37.4 ° C.

Since fever is a symptom and not an independent disease, it is worth seeing a doctor for a diagnosis. To clarify the cause of the development of a febrile state, a number of studies are prescribed: a general blood test, a general urinalysis, a biochemical blood test, a plain X-ray of the chest organs, an ECG, etc.

Treatment

Since during a rise in temperature a metabolic disorder occurs, resulting in general weakness and exhaustion of the body, bed rest is recommended. You should also pay special attention to nutrition. Food should be easily digestible and high in calories. Meals should be divided into 5-6 meals, preference is given to dishes prepared in liquid or semi-liquid form. It is recommended to limit the intake of spicy and spicy foods. Additionally, anyone with a fever should drink plenty of fluids to prevent dehydration and also to help flush toxins out of the body faster.

If the temperature rises above 38°C, antipyretic drugs are prescribed. These include non-steroidal anti-inflammatory drugs (NSAIDs). This group of drugs helps reduce temperatures and eliminate pain, and also has an anti-inflammatory effect. In order to reduce temperature, preference is given to those medications that have the most pronounced antipyretic effect. If the temperature does not reach 38°C, you should not resort to medications, since the body is able to fight such fever figures on its own without disturbing the general condition of the person.

In cases where the fever is caused by a bacterial infection, the doctor will prescribe antibiotics. Their action is aimed at eliminating the immediate cause of the disease, the symptoms of which are fever. Therefore, in the case of competent selection of an antibiotic, a decrease in temperature should occur within the first 3 days of starting to take the drug. If this does not happen, the drug was selected incorrectly, so it is necessary to replace it with one of the representatives of another group of antibiotics. In addition, to ease general well-being and speed up the process of lowering the temperature, NSAIDs are used (together with antibacterial drugs).

If the increase in body temperature is caused by heatstroke, taking NSAIDs is not rational. In this case, the main goal is to cool the body to normal temperature to prevent damage to the brain and other vital organs. For this, ice packs that are placed in the armpits and popliteal fossae, a cold water bath, and cool wraps are suitable. In addition, you can spray the victim’s body with water to enhance the evaporation process, which will lead to a decrease in temperature. It is also recommended to drink plenty of fluids to normalize the water-salt balance.

Medicines

In the treatment of fever, non-steroidal anti-inflammatory drugs (NSAIDs) are used, which have antipyretic, anti-inflammatory and analgesic effects. To reduce fever, preference is given to drugs with a pronounced antipyretic effect.

These include:

Paracetamol. A drug with a pronounced antipyretic effect, due to which the temperature decreases. It is well tolerated by both children and adults, and is therefore often prescribed for the treatment of fever. But it is important to remember that long-term use of paracetamol in large doses has a toxic effect on the liver. Therefore, before taking the drug, you should consult your doctor and ensure that you do not exceed the maximum recommended dose. Paracetamol is included in many powders (Theraflu, ORVIcold, Fervex, etc.).
Aspirin. It still remains relevant due to its low cost and low toxicity. But it is important to remember that in children under 12 years of age, aspirin is contraindicated due to the possibility of developing Reye's syndrome. This syndrome is characterized by severe encephalopathy and toxic liver damage, often leading to death.
Ibuprofen. Available in the form of tablets, syrup, suspension, rectal suppositories. It is used in both adults and children. It has moderate antipyretic, anti-inflammatory and analgesic effects. There is evidence that ibuprofen is able to stimulate the immune system and increase the body's protective properties by influencing the production of endogenous interferon. In the treatment of fever it is inferior to paracetamol, therefore it is a second-line drug.

Since all NSAIDs are, to a greater or lesser extent, capable of affecting the mucous membrane of the gastrointestinal tract with the further development of gastritis and peptic ulcers, it is recommended to take drugs in this group exclusively after meals.

Folk remedies

Treatment of fever with folk remedies can be carried out at home, but it is important to remember that an increase in body temperature very often accompanies severe and dangerous diseases that require immediate medical attention, therefore, to make a diagnosis and prescribe the necessary treatment, you should consult a doctor as soon as possible.

Drinking warm and plenty of fluids helps to bring down the temperature and sweat thoroughly when you have a cold. When sweat is released, natural thermoregulation occurs: sweat begins to evaporate, and the surface of the body cools down. The means that give this effect are berry compotes and fruit drinks, which are recommended to be consumed warm. Cranberries, raspberries, lingonberries, rose hips, and red currants are suitable for preparing such drinks. Fruit drinks and infusions from these berries are a means of increasing sweating; they are also rich in vitamin C. In addition, vitamin C is found in citrus fruits: lemons, oranges, grapefruits.

An infusion of lilac leaves also helps against fever. To prepare it, you need to prepare 20 leaves in advance, which are poured with boiling water and infused for two hours. After filtering, the infusion is taken 2 times a day, 100 ml. The duration of the course is 10 days.

You can also use antipyretic medicinal plants and herbs, for example, nettle, flowers and leaves of clasp, elderberry, rose hips and rowan, linden tea. It should be remembered that when using them, the temperature will not drop immediately, but only after some time.

Cranberry copes well with elevated body temperature. It is a very effective anti-inflammatory, antimicrobial, diuretic and tonic. But do not forget that cranberries can increase the acidity of gastric juice, so those who suffer from gastritis, gastric ulcers and duodenal ulcers should avoid this remedy.

The most popular folk remedy for treating fever is raspberry, popularly called natural aspirin. It is noteworthy that after brewing raspberries with boiling water, all its beneficial properties are only enhanced. This is why we are used to drinking raspberry tea when we have a cold.

The room where there is a person with elevated body temperature must be systematically ventilated. It is also necessary to change bed and underwear frequently, especially if the patient has sweated. While the temperature remains high, bed rest must be observed.

Remember that under no circumstances should you self-medicate, but should consult a doctor!

The information is for reference only and is not a guide to action. Do not self-medicate. At the first symptoms of the disease, consult a doctor.

Fever is a protective-adaptive mechanism of the human body that develops as a reaction to the influence of pathogenic stimuli. Sometimes fever also occurs with non-infectious illnesses. This is how the body reacts to the action of endotoxins, endogenous pyrogens, which are released when they are destroyed, a septic inflammatory process occurs, and metabolic disorders and autoimmune processes are also observed.

How does fever manifest?

The processes of thermoregulation in the human body are determined by the thermoregulation center, which is located in the person. These processes may be disrupted exogenous or endogenous factors. Sometimes the temperature rises in the event of a disturbance in the processes of heat production and heat transfer and in the normal state of the thermoregulation center.

The main manifestations of fever are increased body temperature. If normal body temperature, measured in the armpit, should be 36.0-36.9, then with fever these indicators increase. With a fever, a person experiences chills, headache, weakness, and severe muscle aches.

Classification of fevers is practiced depending on various factors. Taking into account the reason for the development of this condition, it is determined infectious And non-infectious fever.

Taking into account the level of increase in body temperature, the patient varies low-grade fever fever (body temperature 37-37.9 °C), febrile fever (body temperature 38-38.9 °C), pyretic or high fever (body temperature 39-40.9 °C) And hyperpyretic or excessive fever (body temperature 41 °C and more).

Depending on the duration of this condition, it varies acute , subacute And chronic fever.

According to the assessment of body temperature indicators and the time when they appear, it is determined constant , laxative , intermittent , returnable , wavy , wrong , perverted , hectic fever. All types of fever have peculiarities of their course. For example, hectic fever develops with strong fluctuations in body temperature. These types of fever appear with the development of certain diseases.

A number of diseases associated with fever and associated symptoms are identified.

Types of fevers

Crimean hemorrhagic fever is a viral disease that develops as a result of exposure to a pathogen transmitted by ticks. Crimean fever was first diagnosed in Crimea. Signs of this disease were discovered in 1944. Its causative agent is RNA virus, which enters the body through the skin when a person is bitten by a tick.

Symptoms of hemorrhagic fever manifest themselves acutely: body temperature rises sharply, intoxication is noted, as well as hemorrhagic syndrome (high level of bleeding). The patient may be bothered by vomiting, and in the initial period there is noticeable redness of the face. After 2-6 days, hemorrhagic syndrome is observed, which is characterized by the appearance hemorrhagic rash on the shoulders, feet, hands.

If hemorrhagic fever with renal syndrome develops, then the acute onset of fever is combined with symptoms of intoxication and serious kidney damage. As a consequence, hemorrhagic renal fever leads to kidney damage and liver failure. There is bleeding from the gums, nosebleeds, and the person may lose consciousness. Viral diseases associated with hemorrhagic syndrome, are also dangerous because a person may develop bleeding in the stomach and intestines. Development of complications ( sepsis , pulmonary edema , pneumonia ) and improper treatment can be fatal. Therefore, prevention of infection is important: immediately after a tick bite, you need to consult a specialist. Far Eastern hemorrhagic fever is a serious disease that requires urgent treatment.

Prolonged fever of unknown origin can be diagnosed if the body temperature is high (above 38 degrees) lasts for more than two weeks in the patient, and the reasons for this phenomenon remain unknown. At the same time, a comprehensive examination was carried out and all diagnostic standards were taken into account. A very important point is the differential diagnosis of fever of unknown origin, since sometimes this diagnosis can be made incorrectly. According to some experts, this type of fever is based on infection, the development of a malignant tumor, and systemic connective tissue diseases. Approximately at 20% In cases of this type of fever, both in children and adults, the cause remains unclear. Treatment of the disease is prescribed depending on the intensity of the fever.

Yellow fever humans become infected from animals and people; the pathogen is transmitted by mosquitoes. The first symptoms of yellow fever appear approximately 3-6 days after a mosquito bite. The onset of yellow fever is acute: body temperature rises to 40 degrees, severe headache and pain in the joints, back, and legs appear. There is also a hemorrhagic component: the patient’s face becomes very red and swollen. Already on the second day the person suffers from severe vomiting, nausea and thirst. Around the fifth day, a period of remission begins when the person begins to feel better. But this improvement only lasts a few hours. Then the person becomes worse, as thrombohemorrhagic syndrome develops. Bleeding and bloody vomiting are possible. The disease is fraught with the development of serious complications - sepsis , pneumonia , myocarditis . Treatment of this disease consists of symptomatic therapy and prevention of further progression of the disease. The main preventive measures are vaccination. Vaccination against yellow fever is mandatory if a person travels to areas where this disease is endemic. More than 45 endemic countries have been identified in Latin America And Africa, when traveling to which it is necessary to get vaccinated ( Colombia, Peru, Brazil, Ecuador, Kenya and etc.)

After making a diagnosis, the doctor prescribes treatment for the disease that has been diagnosed. It is important not to delay contacting a specialist for conditions that cause anxiety. Eg, white fever Children exhibit inadequate heat transfer, so there is a danger of serious overheating of the body. In this case, you should consult a doctor immediately to determine the causes of this condition and prescribe treatment. You should consult your doctor if your child has post-immunization fever , that is, an increase in temperature after vaccinations.

If a woman exhibits milk fever , that is, the body’s reaction to the appearance of milk in the breasts of a nursing mother, you should not wait until this condition goes away on its own. This is fraught with complications, so the breast must be examined by a doctor.

Fever on the lips (as people call rashes) periodically appears in people who are infected with the herpes virus. Doctors still don’t know how to cure herpes completely. However, local remedies can reduce the manifestations of the disease. How to treat lip fever is worth asking your doctor.

Under fever of unknown origin(LNG) refers to clinical cases characterized by a persistent (more than 3 weeks) increase in body temperature above 38°C, which is the main or even the only symptom, while the causes of the disease remain unclear, despite intensive examination (conventional and additional laboratory techniques). Fevers of unknown origin can be caused by infectious and inflammatory processes, cancer, metabolic diseases, hereditary pathology, and systemic connective tissue diseases. The diagnostic task is to identify the cause of the increase in body temperature and establish an accurate diagnosis. For this purpose, an extensive and comprehensive examination of the patient is carried out.

ICD-10

R50 Fever of unknown origin

General information

Thermoregulation of the body is carried out reflexively and is an indicator of general health. The occurrence of fever (> 37.2°C for axillary measurements and > 37.8°C for oral and rectal measurements) is associated with the body’s response, protective and adaptive reaction to the disease. Fever is one of the earliest symptoms of many (not only infectious) diseases, when other clinical manifestations of the disease have not yet been observed. This causes difficulties in diagnosing this condition. To establish the causes of fever of unknown origin, a more extensive diagnostic examination is required. The start of treatment, including trial treatment, before the true causes of LNG are established, is prescribed strictly individually and is determined by a specific clinical case.

Causes and mechanism of development of fever

Fever lasting less than 1 week usually accompanies various infections. Fever lasting more than 1 week is most likely due to some serious illness. In 90% of cases, fever is caused by various infections, malignant neoplasms and systemic connective tissue lesions. The cause of fever of unknown origin may be an atypical form of a common disease; in some cases, the cause of the increase in temperature remains unclear.

The mechanism for increasing body temperature in diseases accompanied by fever is as follows: exogenous pyrogens (bacterial and non-bacterial in nature) affect the thermoregulation center in the hypothalamus through endogenous (leukocyte, secondary) pyrogen - a low molecular weight protein produced in the body. Endogenous pyrogen affects the thermosensitive neurons of the hypothalamus, leading to a sharp increase in heat production in the muscles, which is manifested by chills and a decrease in heat transfer due to the narrowing of skin blood vessels. It has also been experimentally proven that various tumors (lymphoproliferative tumors, liver tumors, kidney tumors) can themselves produce endogenous pyrogen. Violations of thermoregulation can sometimes be observed with damage to the central nervous system: hemorrhages, hypothalamic syndrome, organic brain lesions.

Classification of fever of unknown origin

There are several variants of the course of fever of unknown origin:

classic (previously known and new diseases (Lyme disease, chronic fatigue syndrome);
nosocomial (fever appears in patients admitted to the hospital and receiving intensive care, 2 or more days after hospitalization);
neutropenic (number of neutrophils, candidiasis, herpes).
HIV-associated (HIV infection in combination with toxoplasmosis, cytomegalovirus, histoplasmosis, mycobacteriosis, cryptococcosis).

Body temperature is classified according to the level of increase:

subfebrile (from 37 to 37.9 °C),
febrile (from 38 to 38.9 °C),
pyretic (high, from 39 to 40.9 ° C),
hyperpyretic (excessive, from 41°C and above).

The duration of fever can be:

acute - up to 15 days,
subacute - 16-45 days,
chronic – more than 45 days.

Based on the nature of changes in the temperature curve over time, fevers are distinguished:

constant - high (~ 39°C) body temperature is observed for several days with daily fluctuations within 1°C (typhus, lobar pneumonia, etc.);
laxative – during the day the temperature fluctuates from 1 to 2°C, but does not reach normal levels (for purulent diseases);
intermittent – with alternating periods (1-3 days) of normal and very high body temperature (malaria);
hectic – there are significant (more than 3°C) daily or at intervals of several hours temperature changes with sharp changes (septic conditions);
relapsing - a period of increased temperature (up to 39-40°C) is replaced by a period of subfebrile or normal temperature (relapsing fever);
wavy - manifested in a gradual (from day to day) increase and a similar gradual decrease in temperature (lymphogranulomatosis, brucellosis);
incorrect - there is no pattern of daily temperature fluctuations (rheumatism, pneumonia, influenza, cancer);
perverted - morning temperature readings are higher than evening ones (tuberculosis, viral infections, sepsis).

Symptoms of fever of unknown origin

The main (sometimes the only) clinical symptom of fever of unknown origin is a rise in body temperature. For a long time, fever may be asymptomatic or accompanied by chills, excessive sweating, heart pain, and suffocation.

Diagnosis of fever of unknown origin

The following criteria must be strictly observed when diagnosing fever of unknown origin:

The patient's body temperature is 38°C or higher;
fever (or periodic rises in temperature) has been observed for 3 weeks or more;
The diagnosis has not been determined after examinations using generally accepted methods.

Patients with fever are difficult to diagnose. Diagnosis of the causes of fever includes:

general blood and urine analysis, coagulogram;
biochemical blood test (sugar, ALT, AST, CRP, sialic acids, total protein and protein fractions);
aspirin test;
three-hour thermometry;
Mantoux reaction;
X-ray of the lungs (detection of tuberculosis, sarcoidosis, lymphoma, lymphogranulomatosis);
Echocardiography (exclusion of myxoma, endocarditis);
Ultrasound of the abdominal cavity and kidneys;
consultation with a gynecologist, neurologist, ENT doctor.

To identify the true causes of fever, additional studies are used simultaneously with generally accepted laboratory tests. For this purpose the following are appointed:

microbiological examination of urine, blood, nasopharyngeal swab (allows to identify the causative agent of infection), blood test for intrauterine infections;
isolation of a viral culture from body secretions, its DNA, titers of viral antibodies (allows you to diagnose cytomegalovirus, toxoplasmosis, herpes, Epstein-Barr virus);
detection of antibodies to HIV (enzyme-linked immunosorbent complex method, Western blot test);
microscopic examination of a thick blood smear (to rule out malaria);
blood test for antinuclear factor, LE cells (to exclude systemic lupus erythematosus);
performing a bone marrow puncture (to exclude leukemia, lymphoma);
computed tomography of the abdominal organs (exclusion of tumor processes in the kidneys and pelvis);
skeletal scintigraphy (detection of metastases) and densitometry (determination of bone tissue density) for osteomyelitis, malignant tumors;
examination of the gastrointestinal tract using radiation diagnostics, endoscopy and biopsy (for inflammatory processes, tumors in the intestine);
carrying out serological reactions, including indirect hemagglutination reactions with the intestinal group (for salmonellosis, brucellosis, Lyme disease, typhus);
collection of data on allergic reactions to drugs (if a drug disease is suspected);
study of family history in terms of the presence of hereditary diseases (for example, familial Mediterranean fever).

To make a correct diagnosis of fever, anamnesis and laboratory tests can be repeated, which at the first stage could have been erroneous or incorrectly assessed.

Treatment of fever of unknown origin

If the patient's fever is stable, treatment should be withheld in most cases. Sometimes the issue of conducting a trial treatment for a patient with fever is discussed (tuberculostatic drugs for suspected tuberculosis, heparin for suspected deep vein thrombophlebitis, pulmonary embolism; antibiotics fixed in bone tissue for suspected osteomyelitis). The prescription of glucocorticoid hormones as a trial treatment is justified in cases where the effect of their use can help in diagnosis (if subacute thyroiditis, Still's disease, polymyalgia rheumatica is suspected).

It is extremely important when treating patients with fever to have information about possible previous medication use. The reaction to taking medications in 3-5% of cases can be manifested by an increase in body temperature, and be the only or main clinical symptom of hypersensitivity to drugs. Drug fever may not appear immediately, but after a certain period of time after taking the drug, and is no different from fevers of other origins. If drug fever is suspected, discontinuation of this drug and monitoring of the patient is required. If the fever disappears within a few days, the cause is considered clarified, and if the elevated body temperature persists (within 1 week after stopping the medication), the medicinal nature of the fever is not confirmed.

There are different groups of drugs that can cause drug fever:

antimicrobials (most antibiotics: penicillins, tetracyclines, cephalosporins, nitrofurans, etc., sulfonamides);
anti-inflammatory drugs (ibuprofen, acetylsalicylic acid);
medicines used for gastrointestinal diseases (cimetidine, metoclopramide, laxatives containing phenolphthalein);
cardiovascular drugs (heparin, alpha-methyldopa, hydralazine, quinidine, captopril, procainamide, hydrochlorothiazide);
drugs acting on the central nervous system (phenobarbital, carbamazepine, haloperidol, chlorpromazine thioridazine);
cytostatic drugs (bleomycin, procarbazine, asparaginase);
other drugs (antihistamines, iodide, allopurinol, levamisole, amphotericin B).

Fever is an increase in a person’s body temperature, which occurs due to disruption of the body’s thermoregulation processes. Fever most often develops with infectious diseases.

A febrile state is provoked pyrogens(products of the breakdown of microorganisms) formed in the patient’s body and changing the functional activity of thermoregulation centers.

Fever may accompany non-infectious inflammatory processes caused by physical or chemical damage; necrotic tissue degeneration caused by circulatory disorders; some endocrine pathologies; malignant neoplasms; allergic reactions, etc.

Fever is a dangerous symptom, and in some cases can play an unfavorable role in the outcome of the disease. Keep in mind that different people tolerate heat differently. For example, older people can survive serious illnesses such as acute pneumonia without significant fever.

In some cases, for therapeutic purposes, an artificial increase in the patient’s body temperature is carried out, for example, during sluggish infectious processes.

Classification of febrile conditions depending on body temperature:

up to 38°C - low-grade fever;
38-39°C - moderate fever;
39-41°C - high fever;
above 41°C - excessive fever.

Often the degree of fever is subject to a circadian rhythm - in the evening the temperature rises; in the morning it decreases.

Classification of fevers by duration:

hours - fleeting fever;
up to 15 days - acute fever;
15-45 days - subacute fever;
more than 45 days - chronic fever.

Types of chronic fever (types of temperature curves)

Persistent fever- daily fluctuations in the patient’s body temperature do not exceed 1°C (for example, with lobar pneumonia).

Remitting (laxative) fever - daily fluctuations in the patient’s body temperature exceed 1°C, with periods with normal temperature.

Remitting (intermittent) fever - daily fluctuations in the patient’s body temperature exceed 1°C, in the absence of periods with normal temperature.

Hectic (depleting) fever is a sharp jump in the patient’s body temperature from normal values to 40-41°C, which can occur several times during the day, significantly depleting and worsening the patient’s condition (for example, with sepsis).

Perverted (wrong) fever - the patient’s body temperature in the evening hours is lower than in the morning, and there is no daily pattern of temperature fluctuations.

Caring for the sick during a fever

The onset of fever manifests itself as general malaise, headache, and muscle tremors. The patient should be put to bed and kept warm.

The second stage of the febrile process is characterized by a relative balance of the processes of heat production and heat transfer, the patient’s body temperature is constantly elevated, general weakness, headache, and dry mouth are observed. At the peak of the fever, hallucinations are possible, and in children - convulsions. Patients are advised to drink plenty of fluids and eat small meals. When staying in bed for a long time, bedsores are prevented.

During the third stage of fever, heat transfer processes prevail over heat production processes, which is accompanied by increased sweating.

During the febrile process, the patient’s body temperature can change either gradually over several days (lysis) or abruptly over several hours (crisis). A crisis carries a high risk of the patient developing collapse, manifested by acute vascular insufficiency, profuse sweating, pale skin, low blood pressure, increased heart rate, which loses its filling, becoming thread-like. Crisis conditions require medical intervention - the patient is prescribed medications that stimulate the respiratory center, promote increased heart contractions, and increased blood pressure.

A febrile patient requires constant monitoring. In case of dysfunction of the respiratory and circulatory organs, it is necessary to prevent the development of severe complications in time.

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