What causes fever in babies. How to recognize fever symptoms in infants. When does a baby’s temperature indicate a fever. What are the potential complications of infant fevers. How to treat fever in babies safely and effectively.

What Is Considered a Fever in Babies?

Understanding what constitutes a fever in infants is crucial for parents and caregivers. A child’s normal temperature can fluctuate based on age, activity level, and time of day. Generally, the following temperatures are considered true fevers:

• Rectal temperature: 100.4°F (38°C) or higher
• Oral temperature: 100°F (37.8°C) or higher
• Axillary (armpit) temperature: 99°F (37.2°C) or higher

It’s important to note that infants tend to have higher temperatures than older children. Additionally, body temperature is typically highest in the late afternoon and early evening, while lowest at night and early morning.

How to Accurately Measure Your Baby’s Temperature

Accurately measuring your baby’s temperature is essential for determining if they have a fever. Here are some key points to remember:

• Always use a thermometer to measure temperature
• Avoid relying on touch alone, as it can be inaccurate
• Temperature-sensitive tape or “fever strips” are not reliable
• For babies under 6 months, avoid using ear thermometers

For infants, a rectal thermometer is often the most accurate method. However, it’s essential to consult with your pediatrician about the best method for your child’s age and condition.

Common Causes of Fever in Babies

Fever in babies can be caused by various illnesses and conditions. Some of the most common causes include:

1. Ear infections
2. Common colds
3. Urinary tract infections
4. Throat or sinus infections
5. Intestinal (bowel) infections
6. Respiratory Syncytial Virus (RSV)
7. Croup
8. Influenza (flu)
9. Pneumonia

While these are common causes, it’s important to note that more serious conditions such as blood infections (sepsis) and infections of the brain and spinal cord (meningitis) can also cause fever in infants.

Fever in Newborns: When to Seek Immediate Medical Attention

Fever in newborns requires special attention and immediate medical care. Infants younger than two months old with a fever need prompt medical evaluation, even if they appear well and show no other signs of illness. This is because young infants can have serious underlying infections that can rapidly progress.

About 10% of young infants with fever are found to have urinary tract infections, with the rate being even higher in uncircumcised boys. Therefore, having a urine sample checked is crucial in these cases.

Steps to Take If Your Newborn Has a Fever

1. Contact your healthcare provider immediately
2. Discuss the necessary steps for evaluation and treatment
3. Follow your doctor’s advice carefully
4. Monitor your baby’s condition closely

Febrile Convulsions: Understanding and Managing Fever-Induced Seizures

Febrile convulsions are seizures triggered by fever in children between 6 months and five years of age. While they can be frightening for parents, it’s important to understand that they are generally harmless and do not cause lasting damage to the brain or nervous system.

Symptoms of Febrile Convulsions

• Odd facial expression
• Stiffening or twitching
• Rolling of the eyes
• Brief unresponsiveness

These seizures typically last less than a minute, sometimes only a few seconds. If your baby experiences a febrile convulsion, inform your pediatrician promptly for proper evaluation and guidance.

Heatstroke vs. Fever: Recognizing the Difference

It’s crucial to distinguish between fever and heat-related illness, such as heatstroke. Unlike fever, which is caused by infection, heatstroke is a dangerous condition resulting from environmental heat and dehydration.

Key Differences Between Fever and Heatstroke

• Cause: Fever is caused by infection, while heatstroke is caused by environmental factors
• Temperature: Heatstroke can raise body temperature to dangerous levels (above 105°F or 40.5°C)
• Onset: Fever develops gradually, while heatstroke can occur rapidly in certain conditions
• Treatment: Fever may resolve on its own or with medication, while heatstroke requires immediate medical attention

Never leave your baby alone in a closed car, even for a few minutes, as this can quickly lead to heatstroke. Additionally, be cautious about overdressing your baby in hot, humid weather.

Teething and Fever: Separating Fact from Fiction

Many parents wonder if teething can cause fever in babies. While teething, which often starts around 6 months of age, can cause a slight rise in body temperature, research shows it does not cause a true fever.

Teething Symptoms vs. Fever Symptoms

• Teething may cause mild irritability, drooling, and gum sensitivity
• Fever associated with illness often includes other symptoms like lethargy, loss of appetite, or congestion
• A true fever is typically above 100.4°F (38°C) when measured rectally

If your baby has a temperature above the normal range during teething, it’s important to consider other potential causes and consult with your pediatrician.

Managing Fever in Babies: Safe and Effective Strategies

When your baby has a fever, the goal is to keep them comfortable and prevent dehydration. Here are some strategies to manage fever in babies:

1. Keep your baby hydrated with frequent feedings or offering water (if age-appropriate)
2. Dress your baby in lightweight clothing
3. Ensure the room temperature is comfortable, not too hot or cold
4. Use a fever-reducing medication as recommended by your pediatrician
5. Monitor your baby’s temperature and overall condition

Remember, fever is often a sign that the body is fighting off an infection. While it’s important to manage your baby’s comfort, the underlying cause of the fever should be addressed.

When to Seek Medical Attention for Baby Fever

• Any fever in infants under 2 months old
• Fever lasting more than 24 hours in babies 2-3 months old
• Fever lasting more than 3 days in babies over 3 months old
• Signs of dehydration, such as dry mouth or decreased urination
• Unusual irritability or lethargy
• Presence of other concerning symptoms like rash, vomiting, or difficulty breathing

Always trust your instincts as a parent. If you’re concerned about your baby’s fever or overall health, don’t hesitate to contact your healthcare provider for guidance.

Fever and Your Baby – HealthyChildren.org

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Health Issues

Health Issues

​​​​​When your baby has a
fever, especially if it’s their first one, it can be alarming. Keep in mind that fever, which is
sign or symptom of illness, is usually a good sign that the body is fighting off an infection. But it’s important to figure out the cause of your baby’s fever so it can be treated, and to help keep your child
hydrated and comfortable.

What’s considered a fever?

A child’s normal temperature can vary, depending on age and activity level. Time of day can also affect the reading. Body temperature is highest in the late afternoon and early evening, for example, and lowest at night and early morning. Plus, infants tend to have higher temperatures than older children. Generally, these are considered true fevers:

How do I know if my baby has a fever?

Whenever you think your child has a fever, take their temperature with a
thermometer. Feeling their forehead or other parts of the body is not accurate, especially if your baby is having chills. Using temperature sensitive tape or “fever strips” also is not reliable. Avoid using an ear thermometer for babies under 6 months old, since their ear canals are too small to allow an accurate reading.

Causes of fever in babies

Fever in babies can develop with illnesses such as:

• 
  Ear infections

• 
  Common colds

• Urinary tract infections

• Throat or sinus infections

• Intestinal (bowel) infections

• RSV

• 
  Croup

• 
  Influenza (flu)

• 
  Pneumonia

The most serious conditions that can cause fever are infections blood (sepsis) and the brain and spinal cord (meningitis​).

Fever in newborns

Infants younger than two months old​ who have a fever need immediate medical attention, even if they appear well and show no other signs of being ill. The challenge is to find the cause of the fever quickly while avoiding putting the baby through unnecessary tests or hospitalizations. 

About 10% of young infants with fever are found to have urinary tract infections. The rate is even higher in uncircumcised boys. That’s why having a urine sample checked is important. However, young infants can have more serious underlying infections that can rapidly progress. If your newborn develops a fever, contact your health care provider, without delay, and discuss steps needed to evaluate and treat your baby.

Febrile convulsions

In children between 6 months old and five years of age, fever can trigger seizures. These are called
febrile convulsions. A child may get an odd look on their face for a few moments, then stiffen or twitch, roll their eyes, and become unresponsive for a short time. Febrile convulsions typically last less than a minute—or even just a few seconds–though it can seem forever to a frightened parent. Thankfully, febrile convulsions are not common and almost always are harmless, causing no lasting damage to the brain or nervous system. However, if your baby has a febrile convulsion, be sure to tell your pediatrician promptly.

Raised body temperature from heatstroke

Fever should not be confused with
heat-related illness, or
heatstroke. This is not caused by infection. Instead, this dangerous condition is caused by surrounding
heat in their environment and dehydration. With heatstroke, body temperature can rise to dangerous levels (above 105 degrees Fahrenheit [40.5 degrees Celsius]). Dozens of children die each year when left unattended in closed,
overheated cars, for example. Never leave your baby alone in closed car, even for a few minutes. Babies can also develop heatstroke if
overdressed in hot, humid weather.

If you think your child has heatstroke,
call 911 or go to the emergency department right away.

Does teething cause fever?

Teething, which often starts at about 6 months of age, can cause a slight rise in your baby’s body temperature within the normal range. However, research shows teething does not cause a true fever. 

More inform​ation

• 
  How to Take a Child’s Temperature
• 
  Fever without Fear: Information for Parents
• 
  Symptom Viewer: Fever

• Fever in Newborns: Treatment for ​​Babies Who Otherwise Seem Well​

Last Updated

7/19/2021

Source

Adapted from Caring for Your Baby and Young Child: Birth to Age Five 7th edition (Copyright © 2019 American Academy of Pediatrics)

The information contained on this Web site should not be used as a substitute for the medical care and advice of your pediatrician. There may be variations in treatment that your pediatrician may recommend based on individual facts and circumstances.

Fever (0-12 Months)

Is this your child’s symptom?

• An abnormal high body temperature
• Fever is the only symptom. Your child has a true fever if:
• Rectal (bottom), Ear or Forehead temperature: 100.4° F (38.0° C) or higher
• Under the arm (armpit) temperature: 99° F (37.2° C) or higher
• Caution: Ear temperatures are not accurate before 6 months of age
• Caution: Forehead temperatures must be digital. Forehead strips are not accurate.

Causes of Fever

• Overview. Almost all fevers are caused by a new infection. Viruses cause 10 times more infections than bacteria. The number of germs that cause an infection are in the hundreds. Only a few common ones will be listed.
• Viral Infections. Colds, flu and other viral infections are the most common cause. Fever may be the only symptom for the first 24 hours. The start of viral symptoms (runny nose, cough, loose stools) is often delayed. Roseola is the most extreme example. Fever may be the only symptom for 3 to 5 days. Then a rash appears.
• Bacterial Infections. A bladder infection is the most common cause of silent fever in girls.
• Vaccine Fever. Fever with most vaccines begins within 12 hours. It lasts 2 to 3 days. This is normal and harmless. It means the vaccine is working.
• Newborn Fever (Serious). Fever that occurs during the first 3 months of life can be serious. All of these babies need to be seen as soon as possible. The fever may be due to sepsis (a bloodstream infection). Bacterial infections in this age group can get worse quickly. They need rapid treatment.
• Meningitis (Very Serious). A bacterial infection of the membrane that covers the spinal cord and brain. The main symptoms are a stiff neck, headache and confusion. Younger children are lethargic or so irritable that they can’t be consoled. If not treated early, can suffer brain damage.
• Overheated. The fever is usually low grade. Can occur during heat waves or from being overdressed. The temp becomes normal in a few hours after moving to a cooler place. Fever goes away quickly with rest and drinking extra fluids.
• Not Due to Teething. Research shows that “getting teeth” does not cause fevers.

Fever and Crying

• Fever on its own shouldn’t cause much crying.
• Frequent crying in a child with fever is caused by pain until proven otherwise.
• Hidden causes can be ear infections, kidney infections, sore throats and meningitis.

Normal Temperature Range

• Rectal. A reading of 98.6° F (37° C) is just the average rectal temp. A normal low can be 96.8° F (36° C) in the morning. It can change to a high of 100.3° F (37.9° C) late in the day. This is a normal range.

When to Call for Fever (0-12 Months)

Call 911 Now

• Not moving
• Can’t wake up
• Severe trouble breathing (struggling for each breath; can barely speak or cry)
• Purple or blood-colored spots or dots on skin
• You think your child has a life-threatening emergency

Call Doctor or Seek Care Now

• Trouble breathing, but not severe
• Great trouble swallowing fluids or spit
• Fever in baby less than 12 weeks old. Caution: Do NOT give your baby any fever medicine before being seen.
• Fever over 104° F (40° C)
• Shaking chills (shivering) lasting more than 30 minutes
• Nonstop crying or cries when touched or moved
• Won’t move an arm or leg normally
• Dehydration suspected. No urine in over 8 hours, dark urine, very dry mouth and no tears.
• Weak immune system. Examples are sickle cell disease, HIV, cancer, organ transplant, taking oral steroids.
• Your child looks or acts very sick
• You think your child needs to be seen, and the problem is urgent

Contact Doctor Within 24 Hours

• Age 3-6 months old with fever
• Age 6-12 months old with fever that lasts more than 24 hours. There are no other symptoms (such as cough or diarrhea).
• Fever lasts more than 3 days
• Fever returns after gone for more than 24 hours
• You think your child needs to be seen, but the problem is not urgent

Contact Doctor During Office Hours

• You have other questions or concerns

Self Care at Home

• Fever with no other symptoms and your child acts mildly ill

Seattle Children’s Urgent Care Locations

If your child’s illness or injury is life-threatening, call 911.

• 
  
  
  
  
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• 
  
  
  
  
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• 
  
  
  
  
  Federal Way
  
  
  
• 
  
  
  
  
  Seattle
  
  
  
• 
  
  
  
  
  Virtual Urgent Care
  
  
  

Care Advice for Fever

1. What You Should Know About Fever:
   • Having a fever means your child has a new infection.
   • It’s most likely caused by a virus.
   • You may not know the cause of the fever until other symptoms develop. This may take 24 hours.
   • For infants more than 3 months old, most fevers are good for sick children. They help the body fight infection.
   • Use the ranges below to help put your child’s level of fever into perspective:
   • 100° – 102° F (37.8° – 39° C) Low grade fever: helpful, good range. Don’t treat.
   • 102° – 104° F (39 – 40° C) Average fever: helpful. Treat if causes discomfort.
   • Over 104° F (40° C) High fever: causes discomfort, but harmless. Always treat.
   • Over 106° F (41.1° C) Very high fever: important to bring it down. Rare to go this high.
   • Over 108° F (42.3° C) Dangerous fever: fever itself can be harmful.
2. Treatment for All Fevers – Extra Fluids:
   • Fluids alone can lower the fever. Reason: being well hydrated helps the body give off heat through the skin.
   • For shivering (or the chills), give your child a blanket. Make them comfortable.
   • Offer your child extra water or other fluids by mouth. Cold fluids are better. Until 6 months old, only give extra formula or breastmilk.
   • For all children, dress in 1 layer of light weight clothing, unless shivering. Reason: also helps heat loss from the skin.
   • For shivering (or the chills), give your child a blanket. Make them comfortable.
   • Caution: if a baby under 1 year has a fever, never overdress or bundle up. Reason: Babies can get over-heated more easily than older children.
3. Fever Medicine:
   • Caution: Do not give a baby under 3 months any fever medicine. Most of these babies will need to be seen.
   • For fevers 100°-102° F (37.8° – 39°C), fever meds are not needed. Reason: fevers in this range help the body fight the infection. Fevers turn on the body’s imune system. Fevers don’t cause any discomfort.

   Fever meds are mainly needed for fevers higher than 102° F (39° C).

4. Give an acetaminophen product (such as Tylenol).
5. Another choice is an ibuprofen product (such as Advil) if over 6 months old.
6. Goal of treatment: keep the fever at a helpful level. Most often, the fever meds lower the fever by 2° to 3° F (1 – 1.5° C). They do not bring it down to normal. It takes 1 or 2 hours to see the effect.
7. Do not use aspirin. Reason: Risk of Reye syndrome, a rare but serious brain disease.
8. Do not use both acetaminophen and ibuprofen together. Reason: Not needed and a risk of giving too much.
9. Pain: fever does not cause pain. If your child also has pain, it’s from the infection. It may be a sore throat or muscle pain. Treat the pain, if it’s more than mild.
10. Return to Child Care:
    • Your child can return to child care after the fever is gone. Your child should feel well enough to join in normal activities.
11. What to Expect:
    • Most fevers with viral illnesses range between 101° and 104° F (38.4° and 40° C).
    • They may last for 2 or 3 days.
    • They are not harmful.
12. Call Your Doctor If:
    • Your child looks or acts very sick
    • Any serious symptoms occur such as trouble breathing
    • Fever goes above 104° F (40° C)
    • Any fever occurs if less than 12 weeks old
    • Fever without other symptoms lasts more than 24 hours
    • Fever lasts more than 3 days (72 hours)
    • You think your child needs to be seen
    • Your child becomes worse

And remember, contact your doctor if your child develops any of the ‘Call Your Doctor’ symptoms.

Disclaimer: this health information is for educational purposes only. You, the reader, assume full responsibility for how you choose to use it.

Last Reviewed: 07/18/2023

Last Revised: 12/30/2022

Copyright 2000-2023 Schmitt Pediatric Guidelines LLC.

Causes and treatment of white fever in a child – articles from JSC Meditsina

Children’s clinic JSC “Medicina”
(clinic of Academician Roitberg)

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White fever in a child: what does it mean? This phenomenon consists in the fact that the patient’s temperature rises sharply (up to 39 ° C), while the skin of this person, including the child, acquires a pale (that is, white) tint. Although in general a rise in temperature is a positive phenomenon, since in this way the body fights an infection, white fever in a child is a symptom that has a negative meaning. Along with getting rid of harmful viruses and bacteria, this condition can be harmful to the health of the patient.

In general, older relatives are aware of how to deal with fever, and if this symptom occurs on its own, they often call a doctor. But since it can have a certain specific origin, you still need to contact a specialist to establish the original cause of what is happening.

Causes of white fever in children

The cause of white fever in a child is a certain disease or other harm to health, the fever itself in this case acts as a reaction to what happened to the child.

One of the cases is the appearance of an infection in the body of a small patient, and then the body reacts to it in a similar way. White fever in a child very often becomes a consequence of such a common disease as SARS. In addition, various types of trauma, swelling, burns, swelling and hemorrhage will become a prerequisite for it.

Significant emotional stress of a stressful nature can also lead to this manifestation. It is quite capable of leading to white fever in a child and intense pain shock.

In general, there are five key conditions that can cause this condition in a young patient:

• infection in the acute stage;
• virus infection, if the patient has a respiratory disease, then such a symptom may appear on the first day;
• bacterial infection for which the wrong therapy was carried out;
• disease caused by inflammation, including pneumonia, otitis media, tonsillitis, rhinitis, pharyngitis;
• diseases of a somatic nature (both chronic and acute).

Symptoms of white fever in children

White fever in a child occurs in three stages.

• Baby’s initial sudden rise in temperature.
• Subsequent stabilization of this indicator.
• Drop in temperature to normal (can be either abrupt or gradual).

Among the symptoms of this condition, mention should be made of fever, although the child’s hands and feet feel cold. The skin of the baby is pale, and if you click on a certain area, then a white spot on it remains for a long time. The reason is that due to a strong spasm in this area, a violation of blood circulation occurs.

A small patient is lethargic and weak, he does not want to eat. Arrhythmia may also occur, the baby’s body may undergo dehydration.

It is worth remembering that these symptoms indicate that the child’s immune system is launched into action, as a result, the body, raising the temperature to 38.5 or 39? C, ensures that the protein of foreign origin that enters the system from the outside coagulates. The problem is that white fever is a dangerous disease, because if this temperature is maintained for a certain time, convulsions can begin, and dehydration will also occur. As a result, the child’s life is in danger.

In general, this condition is most common in children between birth and three years of age.

When should I see a doctor?

It makes sense to consult a doctor if the temperature persists for a long time, not wanting to subside. Also, an alarming symptom will be the general weakness of the child and a violation of his breathing. If the condition of a small patient is of concern, you need to call a pediatrician.

In the most severe cases of white fever in a child, the doctor can best determine what to do about the condition. Of course, in many cases, parents prefer to deal with the temperature on their own, but it is the doctor who will be able to accurately determine its causes and develop optimal actions.

Diagnosis

Diagnosis of white fever requires a re-measurement of temperature to record that it has reached the mark of 38.5 or 39? It is also required to check his palms and feet to find out if they are cold (this is what is a symptom of this condition).

Treatment

It must be clearly established that this is indeed a dangerous white fever. Treatment of a child in the case when his temperature just rose to 38.5 or 39?C, may not be required if he feels relatively comfortable in this situation.

The room in which the patient remains must in any case be simply warm, not hot. It is necessary that the air is humidified, it is not required to wrap the baby.

Drink should be given to him in plenty, and food – when he wants. Moreover, even if the baby refrains from eating food for quite a long time, it is still impossible to force him to eat. If the child already does not have enough strength, then all the remaining ones can be spent on digesting the incoming food, which will not improve his condition. The recommended drink is various fruit drinks and raspberry jam diluted in water, you can also give water, the main thing is that it all be warm, not hot. But, for example, such a very popular combination as milk and honey, in fact, in the event of a sharp increase in temperature is not recommended. The reason is that the milk curdles inside.

Since the treatment of white fever in a child should be, first of all, by combating the fever. The temperature, when it rises above 39 degrees, should be brought down by giving the child an antipyretic.

Preparations for white fever will be prescribed to the child by a doctor invited by the parents, who will first determine the cause of the condition of the little patient.

• If a sharp rise in temperature occurred due to an infection that is of bacterial origin, then antibiotics should be prescribed to the child, but an antipyretic is not required, since they can bring down the temperature itself, but this will only disguise the fact that it was not possible to cope with the cause.
• Also, the doctor can prescribe both an antipyretic and a second drug, the function of which is to influence the source of the disease, in particular, it can be antiviral, as well as cough medicine.

It should be borne in mind that the action of the antipyretic takes time. If only half an hour has passed after taking it, then with a high probability the temperature simply will not have time to fall. It makes sense to wait for several hours, and after that it will drop in most cases.

At the same time, a drop in this indicator in a child from 39? to 38? C will be quite acceptable, it will not be bad, and if it falls by half a degree, this will also mean that the body is coping with white fever. At the same time, it is not worth stuffing the baby with antipyretics again, after he was given the amount that was prescribed by the doctor. An overdose of these drugs can cause hypothermia when the child’s temperature falls below 36.6°C.

You can also wipe your baby with a damp sponge, but do not rub it with alcohol. This compound negatively affects the body of a small patient. If it is abused, then intoxication can occur as a result, after which its condition will only worsen.

It is also desirable that the parents or other older relatives remain close to the child. The fever in the case when the child is alone is exacerbated by the fear that he experiences in such a situation. When an adult is with him, it has a beneficial effect on him, after which his condition improves.

How to make an appointment with a pediatrician

If the situation has become urgent, you can already dial an ambulance from our clinic, the phone number of which is +7 (495) 775-73-60. You can also contact us through our website using the feedback form.

The employees of our medical center act as quickly as possible. Especially when it comes to an emergency that requires urgent hospitalization. The clinic carries out diagnostics and immediately prescribes the optimal method of treatment that will help your child overcome all the difficulties of the disease as quickly as possible.

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Fever in children. Causes of development and methods of treatment

Body temperature is regulated by thermosensitive neurons localized in the preoptic and anterior hypothalamus. These neurons are responsible for changes in body temperature in the same way as neural connections with cold and heat receptors located in the skin and muscles. Thermoregulatory responses are highly variable, mediated through a variety of mechanisms, and include directing blood flow in the skin vasculature, increased or decreased sweat secretion, regulation of extracellular fluid volume (via arginine vasopressin), or behavioral responses such as seeking warmth or cool ambient temperature. Normally, there is a circadian temperature rhythm or diurnal variations in body temperature within adjustable limits. Body temperature is lower in the morning and approximately 1°C higher in the afternoon and late afternoon.

Fever is a controlled increase in body temperature through mechanisms that regulate normal temperature. The difference is that the “thermostat” of the body is reset to a high temperature. Depending on which disease accompanies fever (infectious, connective tissue disease, malignant process), regulatory mechanisms are triggered in response to endogenous pyrogens, which, in turn, trigger the production of cytokines such as interleukin (IL) 1β and IL-6 , tumor necrotizing factor α, β-interferons and interferon-γ. Stimulated leukocytes and other cells produce lipids that also serve as endogenous pyrogens. The most well-studied lipid mediator is prostaglandin E2. Most endogenous pyrogenic molecules are too large to cross the blood-brain barrier. However, near the hypothalamus, the functions of the blood-brain barrier are insufficient, which allows neurons to contact circulating factors through a network of capillaries.

Microbes, microbial toxins and other waste products of microorganisms are among the most common exogenous pyrogens that, when ingested, stimulate the functions of macrophages and other cells to produce endogenous pyrogens leading to fever. Endotoxin can directly influence thermoregulation in the hypothalamus and stimulate the release of endogenous pyrogens. Some substances formed in the body are not pyrogens, but are able to stimulate the formation of endogenous pyrogens. Such substances include antigen-antibody complexes in the presence of complement, as well as complement components, lymphocyte products, bile acids, and androgenic steroid metabolites. Fever can be the result of infections, vaccination, exposure to biological agents (granulocyte – macrophage – colony stimulating factor, interferons, interleukins), tissue damage (heart attack, pulmonary embolism, trauma, intramuscular injections, burns), malignant diseases (leukemia, lymphoma, metastatic diseases) , taking certain drugs (drug fever, cocaine, amphotericin B), diffuse connective tissue diseases, rheumatic diseases (systemic lupus erythematosus, rheumatoid arthritis), granulomatous diseases (sarcoidosis), endocrine (thyrotoxicosis, pheochromocytoma), metabolic disorders (uremia, gout) , genetic disorders (familial Mediterranean fever) and other unknown and poorly understood causes.

An increase in body temperature in response to microbial attack represents a response that has been observed in reptiles, fish, birds, and mammals. In humans, an increase in body temperature is accompanied by a decrease in the reproduction of microorganisms and an increase in the inflammatory response. Most of the evidence to date suggests that fever is an adaptive response and should only be treated in selected situations.

Although the nature of the temperature curve alone is not often helpful in making a specific diagnosis, observation of fever can provide useful information to the clinician. In general, a single isolated peak is not associated with an infectious disease. Such a peak can be observed with parenteral administration of blood products, drugs, certain procedures or catheter manipulations with an infected skin surface. Temperatures above 41°C are rarely due to an infectious cause. Very high fever (> 41°C) is most commonly central fever (due to CNS dysfunction involving the hypothalamus), malignant hyperthermia, drug fever, fever due to overheating.

Temperature below normal (< 36 °C) is most often associated with exposure to cold, hypothyroidism, overdose of antipyretics.

Intermittent or intermittent fever (daily fluctuations in t° max and t° min of at least 1 ° C, but the minimum body temperature never drops to normal values) is defined as hectic or may be due to sepsis. The remaining persistent fever is persistent, and fluctuations in t ° do not exceed 0.5 ° C per day. With relapsing (laxative) fever, fluctuations in t ° exceed 0.5 ° C during the day, but it does not return to normal. Recurrent (relapsing) fever is separated by intervals of normal temperature, for example, in three-day malaria, fever is observed on the 1st and 3rd days ( Plasmodium vivax ), four days – on the 1st and 4th days ( Plasmodium malariae ). The biphasic nature of Bactrian camel fever indicates the presence of a single disease with two definite periods of fever of more than 1 week. The classic example is polio. Biphasic fever is also observed in leptospirosis, dengue fever, yellow fever, African hemorrhagic fever.

Dependence of heart rate on body temperature can be quite informative. Relative tachycardia, when the pulse rises in proportion to body temperature, is usually observed in non-communicable diseases or infections in which the toxin determines the clinical manifestations. Relative bradycardia (dissociation of pulse and temperature), when the pulse remains low during fever, suggests drug fever, typhoid, brucellosis, leptospirosis. Febrile bradycardia may also be the result of conduction disturbances involving the heart in acute rheumatic fever, Lyme disease, viral myocarditis, and infective endocarditis.

Most infections lead to various lesions causing an inflammatory response and subsequent release of endogenous pyrogens. The appointment of etiotropic antimicrobial therapy can lead to rapid elimination of bacteria. However, if tissue damage is severe, the inflammatory response and fever may continue for several days after eradication of all microbes.

Fever occurs in various infectious diseases with a wide range of severity. In healthy children, benign febrile illnesses include viral infections (rhinitis, pharyngitis, pneumonia), bacterial infections (otitis media, pharyngitis, impetigo), which usually respond well to antibiotic therapy and are not life-threatening. Risk groups include young children, with chronic diseases, immunodeficiency states. Some bacterial infections such as sepsis, meningitis, pneumonia, pyelonephritis, if left untreated, can be severe and have poor outcomes.

Fever without a specific focus usually presents a diagnostic dilemma for pediatricians, especially in children of the first 1.5–2 years of life, making it difficult to differentiate between serious bacterial infections and viral diseases.

Fever in children under 3 months of age always suggests the presence of a serious bacterial disease (sepsis, meningitis, urinary tract infection, gastroenteritis, osteomyelitis, otitis, omphalitis, mastitis, etc. ). Bacteremia may be due to group B streptococcus, Listeria monocytogenes , Salmonella spp., Esherichia coli , Neisseria 20 Streptococcus pneumonia , Haemophilus influenzae type B, Staphylococcus aureus . Children under the age of 3 months with fever, symptoms of intoxication should be hospitalized, blood cultures, urine, cerebrospinal fluid should be examined and parenteral antimicrobial therapy should be started immediately. Unlike bacterial infections, viral diseases tend to be seasonal.

Regardless of age, a fever accompanied by a petechial rash indicates a high risk of life-threatening bacterial infections. 8-10% of patients with fever and petechiae had severe bacterial infections, 7-10% had meningococcal sepsis or meningitis. The disease caused by H.influenzae type B may also present with fever and a petechial rash. Treatment tactics include hospitalization, blood and cerebrospinal fluid culture, and the appointment of appropriate antimicrobial therapy.

Many clinicians use the term “fever of unknown origin” for patients presenting for examination who do not have an obvious infection or a non-infectious diagnosis. In most of these children, the appearance of additional symptoms after a relatively short period of time makes the infectious nature of the disease obvious. Therefore, this term is more often used in patients with fever that is not identifiable after 3 weeks in the outpatient setting or after 1 week in the hospital.

The causes of the so-called fever of unknown origin can be infectious processes and diseases of the connective tissue (autoimmune and rheumatic). It is necessary to exclude a neoplastic process. Most cases of fever of unknown or unrecognized origin are the result of an atypical course of common diseases. Since at the beginning there may be no clinical and laboratory signs of a certain disease, the diagnosis in some cases is made only after prolonged observation. Causes of fever of unknown origin in a more detailed examination included salmonellosis, tuberculosis, syphilis, Lyme disease, atypical protracted course of common viral diseases, infectious mononucleosis, cytomegalovirus infection, hepatitis, histoplasmosis. Inflammatory bowel disease, rheumatic fever, Kawasaki disease can also cause fever of unknown origin. In these cases, it is recommended to re-examine the patient after a certain period of time.

In children under 6 years of age, fever of unknown origin is associated with infection of the respiratory or urogenital tract, localized infection (abscess, osteomyelitis), juvenile rheumatoid arthritis, rarely leukemia. Adolescents are more likely to have tuberculosis, an inflammatory process in the intestines, an autoimmune process, and lymphoma. The empiric use of antibiotics should be avoided. In unclear cases, hospitalization may be required for x-ray and laboratory examinations, closer observation, temporary relief from the anxiety of the child and parents. Once fully adequately assessed, antipyretics may be indicated for fever control and symptomatic treatment.

Fever less than 38–38.5°C in previously healthy children generally does not require treatment. If this level is exceeded, the state of health of patients worsens, and the appointment of antipyretics improves the condition. Antipyretics generally do not change the course of infectious diseases in normal children and are symptomatic. Heat production associated with fever increases oxygen consumption, carbon dioxide production, and cardiac output. Thus, fever may worsen heart failure in patients with heart disease or chronic anemia (eg, sickle cell anemia), pulmonary insufficiency in patients with chronic lung disease, and metabolic disorders in children with diabetes, congenital metabolic disorders. Moreover, in children between 6 months. and 5 years, the risk of febrile seizures is increased, and in children with idiopathic epilepsy, febrile illness may increase the frequency of seizures. Antipyretics are prescribed in high-risk patients, ie. having chronic cardiopulmonary diseases, metabolic, neurological diseases, and children with a high risk of developing febrile seizures. Hyperpyrexia (> 41°C) is associated with severe infections, hypothalamic disorders, and central nervous system hemorrhage and always requires antipyretics.

When choosing antipyretics for children, it is especially important to focus on drugs with the lowest risk of side effects. Currently, only paracetamol and ibuprofen fully meet the criteria for high efficacy and safety and are officially recommended by the World Health Organization and national programs in pediatric practice as antipyretics [1–3]. Acetaminophen, aspirin, and ibuprofen are hypothalamic cyclooxygenase (COX) inhibitors that inhibit the synthesis of PGE-2. These drugs are considered equivalent effective antipyretics. Since aspirin is associated with Reye’s syndrome in children and adolescents, it is not recommended for use in the treatment of fever. Paracetamol and ibuprofen can be prescribed to children from the first months of life (from 3 months of age). Recommended single doses: paracetamol – 10-15 mg / kg, ibuprofen – 5-10 mg / kg. Re-use of antipyretics is possible not earlier than after 4-5 hours, but not more than 4 times a day.

It should be noted that the mechanism of action of these drugs is somewhat different. Paracetamol has an antipyretic, analgesic and very slight anti-inflammatory effect, since it blocks COX mainly in the central nervous system and does not have a peripheral effect, it is metabolized by the cytochrome P-450 system. The delay in the excretion of the drug and its metabolites can be observed in violation of the functions of the liver and kidneys. If a child has a deficiency of glucose-6-phosphate dehydrogenase and glutathione reductase, the administration of paracetamol can cause hemolysis of red blood cells, drug-induced hemolytic anemia.

Ibuprofen has a pronounced antipyretic, analgesic and anti-inflammatory effect. Ibuprofen is effective against fever in the same way as paracetamol [4–6]. A number of studies have shown that the antipyretic effect of ibuprofen at a dose of 7.5 mg/kg is higher than that of paracetamol at a dose of 10 mg/kg and acetylsalicylic acid at a dose of 10 mg/kg [7]. Ibuprofen blocks COX both in the central nervous system and in the focus of inflammation (peripheral mechanism), which determines its antipyretic and anti-inflammatory effect. As a result, the phagocytic production of mediators of the acute phase, including IL-1 (endogenous pyrogen), decreases. A decrease in the concentration of IL-1 also contributes to the normalization of temperature. The analgesic effect of ibuprofen is determined by both peripheral and central mechanisms, which makes it possible to effectively use ibuprofen for mild and moderate sore throat, pain with tonsillitis, acute otitis media, and toothache [8]. An indication for the appointment of ibuprofen is also hyperthermia after immunization.

Due to its high toxicity, amidopyrine has been excluded from the nomenclature of drugs. The use of analgin in many countries of the world is sharply limited due to the risk of developing agranulocytosis. In urgent situations, such as hyperthermic syndrome, acute pain in the postoperative period, and others that are not amenable to other therapy, parenteral use of analgin and metamizole-containing drugs is acceptable.

Comparison in double-blind, randomized trials with multiple doses of antipyretics showed that the incidence of adverse events was similar between ibuprofen and paracetamol (8–9%) [3]. The results of a large randomized study of more than 80,000 children showed that the use of ibuprofen compared with paracetamol does not increase the risk of hospitalization associated with gastrointestinal bleeding, renal failure or anaphylaxis. When using ibuprofen and paracetamol in children with bronchial asthma [3], it has been shown that the use of ibuprofen, compared with acetaminophen, does not increase the risk of bronchospasm in children with bronchial asthma who do not have indications of aspirin intolerance, which indicates the relative safety of ibuprofen in children with bronchial asthma .

According to experts of IC MAKS (Vladimir), paracetamol and ibuprofen are most often used in pediatric practice (Table 1).

We used Nurofen for children (ibuprofen) in 95 children aged 3 months and older. up to 10 years old. The indication was fever in acute respiratory infections, acute otitis media, tonsillopharyngitis, obstructive bronchitis, bronchiolitis, pneumonia. 43 children of the first three years of life were hospitalized in the regional children’s hospital due to the severity of the condition. In 20 children, acute respiratory infections occurred against the background of mild to moderate bronchial asthma without indications of aspirin intolerance, in 37 children obstructive bronchitis and bronchiolitis were diagnosed. The average value of the initial axillary temperature was 39.1 ± 0.6 °С. Nurofen for children was prescribed at the rate of 5 mg/kg, on the first day – 3-4 times, on the second day – 2-3 times; the third day and beyond – according to indications. Most children were prescribed the drug for no more than 2 days. In 40-60 minutes after taking the drug, the temperature decreased to 37.9 ± 0.4 °C, after 90-120 minutes – to 37.3 ± 0.5 °C. Adverse events were noted in 2 children in the form of an allergic rash, in 1 child – abdominal pain, exacerbation or provocation of bronchospasm was not observed in any case. In 6 children, the effect of taking ibuprofen was minimal and short-lived: 2 children were prescribed diclofenac, 4 others received parenteral lytic mixture.