Fever. Variety of reasons and complexity of solutions

Local therapist

Serebryakova

Oksana Evgenievna

Experience 27 years

Local therapist, candidate of medical sciences, member of the Russian Scientific Medical Society of Therapists

Make an appointment

The patient's condition is considered febrile if the body temperature rises above 37.2°C. This condition is not an independent disease, but is regarded as a sign of a serious pathology - an inflammatory process, infection, oncology. Less commonly, body temperature rises when taking certain medications and during heat stroke. Also, the temperature can fluctuate around the specified value during the day - decrease at night during sleep and increase in the evening due to intense exercise. For a healthy person, the range of daily fluctuations usually does not exceed 0.6°C.

Causes of fever

Fever occurs when pyrogens - lipids, proteins, toxins and other substances introduced with viruses, bacteria or allergens - enter the bloodstream.
They interact with cells of the immune system. Because of this, cytokines begin to be produced that affect thermoregulation processes, and body temperature begins to rise. There are many reasons why fever can occur. They can be relatively harmless, for example:

• Recent vaccination.
• In children - teething.
• Overheating if a person has been in a bathhouse or in the sun for a long time in hot weather.
• Eating spicy or hot food.
• Physical activity.

The reasons may be serious and require consultation with a doctor:

• Infectious diseases: influenza and parainfluenza, enterovirus, dysentery, meningitis, fungal, parasitic and other diseases.
• Respiratory diseases: otitis media, pleurisy, pneumonia, bronchitis and others.
• Acute diseases of the digestive system: cholecystitis, pancreatitis, appendicitis and others.
• Kidney diseases: glomerulonephritis, pyelonephritis.
• Autoimmune diseases.
• Sepsis, abscess.
• Intoxication: poisoning with low-quality food, ethanol breakdown products (after drinking alcohol), heavy metals.
• Inflammation of the brain: encephalitis, meningitis, meningoencephalitis.
• Formation of malignant tumors.
• Complication of injuries: deep wounds or fractures, electrical injuries.
• A side effect or consequence of an overdose when taking certain medications.

There are many possible causes of fever, and it is not always possible to accurately determine them. There is a fever of unknown etiology. With it, there are no other symptoms or changes in well-being, and the high temperature persists for up to 3 weeks.

Literature

1. N.V. Orlova, T.G. Suranova. Acute respiratory diseases: clinical features, drug therapy. MEDICAL COUNCIL • No. 15, 2021. pp. 82-88. 2. V.M. Delyagin. Fever (new touches on an ancient painting). Consilium Medicum. Pediatrics. (App.) 2018; 2: pp. 89-93 3. Dvoretsky L.I. Feverish patient. Place and benefits of antipyretics. "RMZh" No. 19 dated 09/07/2011. P. 1166 4. Martynov, A., Malyavin, A., Zhuravleva, M., Bolieva, L., Esaulenko, E., Babak, S., Kalyuzhin, O. Consensus of the expert council of the RNMOT “Improving the results of treatment of respiratory tract infections » Preventive Medicine, 2021, 22(4);144-151 5. Instructions for medical use of the drug TheraFlu® for flu and colds. RU P N012063/01 dated 05/31/2011 6. Tatochenko V.K. Use of antipyretics in children. Issues of modern pediatrics. 2004, volume 3, no. 5, pp. 70-73. 7. Melnikova I.M., Mizernitsky Yu.L. Rational use of antipyretics for acute respiratory diseases in children // Medical Council - No. 2, 2021 - P. 77-81. The trademark belongs to or is used by the GlaxoSmithKline Group of Companies JSC GlaxoSmithKline Healthcare, Russia, 123112, Moscow, Presnenskaya nab., 10, premises III, room 9, floor 6,.

Types of fever

A body temperature of 36.6 degrees Celsius is considered normal, but in a healthy person it may be slightly lower or higher. Body temperature can also change throughout the day—for example, rising slightly after a heavy meal. This is not a fever. A temperature of 37.1°C or higher is considered elevated.

There are four degrees of temperature increase:

• subfebrile - 37.1-38°C;
• moderate - 38.1-39°C;
• high - 39.1-41°C;
• excessive - above 41.1°C.

Fever can be acute (lasts no longer than two weeks and usually resolves within a few days) or subacute (can last up to six weeks).

There are six types of fever, which differ in how the temperature changes:

1. Constant. High temperatures with fluctuations within 1°C last for several days. There is no chills or heavy sweating during the heat.
2. Remitting. Daily temperature fluctuations can be 1-2°C, but it does not drop to normal values. Its decrease may be accompanied by sweating. Chills may occur periodically.
3. Intermittent. Periods of normal and elevated temperatures alternate, and the change in thermometer values ​​can be both sudden and gradual. When the temperature rises, a person feels chills; when it drops, he breaks into a sweat.
4. Perverted. Body temperature is higher in the morning than in the evening.
5. Hectic. With such a fever, daily temperature changes are 3-4°C, and it can drop below normal values.
6. Wrong. There is no pattern in changes in body temperature. Fever is accompanied by sweating and chills.

Mechanism of development and stages of fever

Doctors distinguish three main stages of fever. On the first, a persistent increase in body temperature is recorded, on the second – temperature retention, on the third – a decrease to initial values. Let's take a closer look at all three stages.

An increase in temperature is directly related to the functioning of thermoregulation. As soon as pyrogens begin to affect this system, it begins to rearrange itself in such a way as to increase heat transfer. An interesting fact is that the adult body does not increase heat production, but reduces its consumption, since this saves energy resources. Children's thermoregulation is imperfect and uses a different principle. The body heats up due to increased heat production rather than heat retention.

What happens to the body after exposure to pyrogens? First of all, the peripheral vessels narrow, after which the flow of warm blood into the tissues decreases.

The next stage is a spasm of skin vessels and cessation of sweating (due to signals sent by the sympathetic nervous system). The patient's skin begins to turn pale, and the temperature of the epithelium begins to drop in order to limit heat transfer and conserve resources to combat pathology.

The human condition also undergoes changes. A feeling of chills appears, after which you want to lie down, wrap yourself in a blanket and fall asleep. Chills develop due to a decrease in skin temperature. The brain reacts to temperature changes, provokes muscle tremors and literally forces us to limit activity in order to preserve valuable energy reserves.

As soon as the required temperature is reached, the body begins to maintain it. The process can last from several hours to several weeks. Heat transfer and heat production balance each other, so that no further rise or fall in temperature occurs. At the same time, the skin vessels expand, the skin acquires a natural shade, trembling and chills disappear. A person’s well-being also changes, but not for the better - fever replaces chills.

In the second stage of fever, the temperature can reach the following levels:

• up to 38 °C (low-grade fever);
• 38.5 °C (weak);
• up to 39 °C (febrile or moderate);
• up to 41 °C (pyretic or high);
• over 41 °C (hyperpyretic). Hyperpyretic temperature can be life-threatening, especially for children and older patients.

When the temperature stays the same, it drops. It can be sudden or gradual. A drop in temperature occurs in two cases: the body has exhausted its supply of pyrogens or was able to overcome the root cause of the fever (on its own or with the help of medications). Skin vessels dilate, excess accumulated heat is removed in the form of profuse sweating. Within a few hours, the thermoregulation mechanism returns to its normal state.

Is fever dangerous?

Fever is usually well tolerated by adults and children and is not dangerous. It is important to monitor body temperature values ​​and how it changes. Its sharp and rapid increase to values ​​greater than 40°C can be dangerous.

Important! Fever is more difficult to bear and is more dangerous for older people, for those who have chronic heart or respiratory diseases, endocrine or neurological diseases. Individual heat intolerance is also possible. In this case, seizures may occur with fever.

Complications

Most often, with fever, the temperature rises within 38-40°C. Higher values ​​are dangerous. If the temperature reaches 42°C, the destruction of proteins in cells begins, the release of inflammatory cytokines. Cell function is disrupted. Because of this, failure of most internal organs occurs. This condition leads to death.

In some diseases, fever can cause additional complications. It may worsen cardiac or respiratory failure in patients with chronic heart or respiratory disease. In mental illness, fever can worsen the condition. In children, high fever can cause febrile seizures.

Symptoms and features

As the temperature rises, several characteristic symptoms appear:

• headache;
• chills when the temperature rises and sweating when it drops;
• muscle aches;
• weakness;
• decreased appetite;
• dehydration;
• pain, stinging in the eyes in bright light.

Children may experience some additional symptoms:

• The skin becomes pale or reddened (a blush may appear on the cheeks).
• Decreased appetite or refusal to eat or drink.
• There may be difficulty swallowing food.
• The child may become irritable and lethargic, but sometimes the fever has no effect on behavior or activity.

If you have a high fever, you may experience more severe symptoms, such as seizures, confusion, vomiting, and diarrhea.

Diagnostics

The doctor conducts a thorough history taking, examines the skin and mucous membranes, and palpates the patient’s lymph nodes and abdominal cavity. Prescribes a standard set of laboratory tests that help identify or exclude the causes of fever.

In the process of collecting anamnesis, increased attention is paid to the subject’s recent travels (especially to epidemiologically disadvantaged areas), contacts with people who exhibited similar symptoms, and contacts with animals. The patient is asked to talk in detail about what medications he is taking, the presence of diseases, family history, surgical interventions, injuries, immunizations.

The decision to conduct additional tests is based on the results of the initial assessment and laboratory diagnostic results. An important role is played by serological and virological studies, as well as instrumental diagnostics - radiography, ultrasound, CT, PET, MRI, echocardiography, which can help identify inflammatory processes, malignant tumors, abscesses, diffuse lesions of connective tissue and blood vessels. If necessary, gastroduodenoscopy, bronchoscopy, and biopsy (lymph nodes, bone marrow, liver) may be prescribed.

Diagnosis of the disease: how to measure temperature

To diagnose a fever, body temperature is measured. This can be done in several ways.

To measure the temperature in the armpit, hold the thermometer with your hand in the armpit for about 10 minutes. The skin should be dry and the tip of the thermometer should fit snugly against it.

When measuring the temperature in the rectum before insertion, the tip of the thermometer is lubricated with Vaseline and inserted to a depth of 2 cm through the anus for 1-2 minutes. Rectal measurement is considered the most accurate. It works quickly and is recommended for small children.

To measure the temperature in your mouth, place the tip of the thermometer under your tongue for 3 minutes (or until the digital thermometer beeps). Do not eat or drink anything 15 minutes before thermometry. The method is suitable for adults and children over 4 years old.

To measure the temperature in the ear, an infrared ear thermometer with a specially shaped tip is used. The thermometer is brought to the ear, pointing the sensor towards the ear canal. The measurement is performed before the sound signal. There is no need to insert the tip into the ear canal. The method can be used for children over 6 months and for adults.

Important! Before and after each temperature measurement (especially if it is performed rectally or orally), the tip of the thermometer should be treated with a disinfectant. The same thermometer cannot be used for rectal and oral measurements.

If you don't have a thermometer, you can roughly estimate the temperature by touching it. To do this, you first need to touch your skin, and then the skin of another person: this way you can feel whether it is hot. An indirect sign of fever may be dehydration. To check it, you need to lightly pinch the skin on the back of your hand. If the skin does not straighten immediately, the body may become dehydrated.

Types of thermometers

There are three main types of medical thermometers: mercury, electronic and infrared (Fig. 1). They differ in principle of operation, accuracy and method of application.

Figure 1. Types of medical thermometers. Source: MedPortal

Mercury thermometers

The flask of such a thermometer is filled with mercury, the volume of which decreases or increases with temperature changes. Mercury thermometers are very accurate, have minimal error, and are suitable for measurements in the armpit, orally or rectally. On the other hand, they have a long measurement time. The mercury they contain is hazardous to health, and the thermometers themselves are fragile and prone to breakage. As of 2021, mercury thermometers are banned under the Minamata Convention on Mercury. Russia signed it in 2014.

What to do if a mercury thermometer breaks?

If the mercury thermometer breaks:

1. Remove people and animals from the premises immediately.
2. Wear a wet bandage or mask to protect your respiratory system.
3. Turn off your heating appliances and open a window to lower the air temperature and slow down the evaporation of mercury.
4. Close the door to prevent a draft.
5. Protect your hands with gloves to prevent mercury from coming into contact with your skin.
6. Collect the mercury in a tightly sealed container with water, such as a jar. For collection, you can use a medical syringe, paper, tape or adhesive tape. Do not try to collect mercury with a vacuum cleaner or broom.
7. A jar of mercury can be temporarily placed on the balcony or taken outside, leaving it in a place where it will definitely not break.
8. Do a wet cleaning in the room, wash the floor with plenty of water, without using household chemicals.
9. Hand over the collected mercury at the station of the Ministry of Emergency Situations or SES, to a collection point or demercurization center.

Electronic thermometers

Temperature measurement with an electronic thermometer is performed by contact (the thermometer should touch the skin or mucous membrane). The temperature indicator is determined by measuring the electrical resistance of the conductor. Such thermometers can be used to measure temperature on the skin, rectum, and mouth. Their form can be traditional, in the form of a strip that is glued to the forehead, or in the form of a pacifier (used for small children). The measurement is done quickly. When it is finished, the thermometer beeps. Disadvantages include measurement error and limited service life. When an electronic thermometer's warranty expires, it should be tested periodically to ensure that it measures accurately.

Non-contact thermometers

They react to infrared radiation from human skin and convert it into temperature values. Perform the measurement in a few seconds. They can be ear-shaped (with a specially shaped tip). They do not need to be disinfected before or after use. Disadvantages - high price and error of up to 0.2°C in measurements.

Infrared thermometers measure temperature in a few seconds. Photo: https://ru.freepik.com

When and how should you lower your temperature?

It is not always necessary to use medications to bring down the temperature. As long as it remains within 38.9°C, adults do not need to use antipyretics if they feel normal. The exception is elderly people, as well as people with heart disease, respiratory diseases, neurological and other serious diseases.

Antipyretic or non-steroidal anti-inflammatory drugs are used to reduce temperature. According to the recommendations of the World Health Organization, drugs based on paracetamol and ibuprofen are considered safe (but they should not be used together). For fever, medications are taken only if the fever begins to increase (you do not need to take them constantly). Between doses, be sure to observe the interval recommended by the attending physician or indicated in the instructions for the drug.

At high temperatures, it is important to use non-drug treatments:

• Rest. It is important to stay at home, rest, and stay in bed.
• Drinking regime. Fever causes dehydration, so the patient needs to drink more fluids. This will help remove toxins faster.
• Overheat protection. It is better if the clothes are light and not too warm. The air in the room should be cool. It can be ventilated periodically.
• Rubbing. Rubbing with cool water will help reduce the fever and improve your well-being. To do this, use a damp sponge or napkin, wiping the skin on different parts of the body for several minutes.

At elevated temperatures, it is important to maintain a drinking regime.
Photo: https://ru.freepik.com Important! A cold bath or shower is not always effective in high temperatures. Cool water will cool your body, but it can also cause muscle tremors and chills, which will only make your fever worse.

If a child has a fever, it is important that the temperature does not rise above 38.5°C. To do this, you can give antipyretics recommended by your doctor and make sure that the child does not overheat (no need to wrap him up). When the temperature rises, you can wipe with cool water, but not with alcohol, vodka or vinegar. It is also necessary to exclude dehydration: everything is fine if the child drinks enough, urinates on average once every four hours, and his urine remains light-colored. To correct the fluid balance, the child can be given sweet drinks, juices, compotes, and water. While the fever persists, you need to constantly monitor the child, monitor his condition and consult a doctor if it worsens (Fig. 2).

Figure 2. What to do if a child has a high temperature. Source: MedPortal

Medicines

Photo: lecheniebolezney.com

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:

1. 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.).
2. 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.
3. 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.

When should you see a doctor?

If an adult has a fever, you should consult a doctor if the body temperature rises above 40°C and antipyretics do not help bring it down. A doctor's help is also needed if an elderly person develops a fever, if there is heart disease, respiratory disease, neurological diseases, or a weakened immune system.

If a young child has a fever, see a doctor if the temperature rises above 38°C for those under three months of age or above 39°C for those over three years of age.

An adult needs urgent medical care if the following symptoms appear along with fever:

• Strong headache;
• breathing problems and throat swelling;
• vomit;
• pain in the abdomen or when urinating;
• severe chest pain;
• confusion;
• convulsions;
• rapid spread of skin rash throughout the body.

If a child has a fever, you should call an ambulance under any of the following conditions:

• The baby's temperature rises (up to 2 months of age).
• There are signs of severe dehydration (rare urination, dry mucous membranes and tongue, drowsiness or agitation, restlessness, no tears when crying).
• Convulsions appear.
• A rash spreads across the body or bruises appear.
• Breathing is difficult, slow or too fast, intermittent.
• Apathy and drowsiness appear, and the child cannot be awakened.
• Vomit.
• Strong headache.

You should consult a doctor as soon as possible, within a few hours, if antipyretics do not help bring down the temperature, if the child is less than 6 months old, his condition is worsening, or there is a risk of dehydration due to refusal to drink, diarrhea, and vomiting.