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Viral fever child duration: What to Know and When to Worry


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
  • Oral (Mouth) temperature: 100° F (37.8° 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.
  • Sinus Infection. This is a problem caused by a cold. The main symptom is the return of fever after it has been gone for a few days. The sinus congestion also changes to sinus pain. Color of nasal discharge is not very helpful for making this diagnosis.
  • 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. Can also occur during hard exercise. 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.

Roseola: Classic Cause of Unexplained Fever in Young Children

  • Most children get Roseola between 6 months and 3 years of age.
  • Cause: human herpes virus 6
  • Rash: pink, small, flat spots on the chest and stomach. Rash is the same on both sides of the body.
  • Then spreads to the face.
  • Classic feature: 2 or 3 days of high fever without a rash or other symptoms.
  • The rash starts 12 to 24 hours after the fever goes away.
  • The rash lasts 1 to 3 days.
  • By the time the rash appears, the child feels fine.

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.
  • By mouth. A reading of 97.6° F (36.5° C) is just the average mouth temp. A normal low can be 95.8° F (35.5° C) in the morning. It can change to a high of 99.9° F (37.7° C) late in the day. This is a normal range.

When to Call for Fever

Call 911 Now

  • Not moving or too weak to stand
  • 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 more than 8 hours, dark urine, very dry mouth and no tears.
  • Pain or burning when passing urine
  • 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 6-24 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 being gone more than 24 hours
  • Recent travel outside the country to high risk area
  • 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.

  • Bellevue

  • Everett

  • 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.
    • 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.
    • 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:
    • 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 immune system. Fevers do not cause any discomfort.
    • Fever meds are mainly needed for fevers higher than 102° F (39° C).
    • Give an acetaminophen product (such as Tylenol).
    • Another choice is an ibuprofen product (such as Advil).
    • 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.
    • Do not use aspirin. Reason: risk of Reye syndrome, a rare but serious brain disease.
    • Do not use both acetaminophen and ibuprofen together. Reason: not needed and a risk of giving too much.
    • 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.
  4. Sponging with Lukewarm Water:
    • Note: sponging is an option for high fevers, but not required. It is rarely needed.
    • When to Use: fever above 104° F (40° C) AND doesn’t come down with fever meds. Always give the fever medicine at least an hour to work before sponging.
    • How to Sponge: use lukewarm water (85 – 90° F) (29.4 – 32.2° C). Sponge for 20-30 minutes.
    • If your child shivers or becomes cold, stop sponging. Other option: you can also make the water warmer.
    • Caution: do not use rubbing alcohol. Reason: can cause a coma.
  5. Return to School:
    • Your child can return to school after the fever is gone. Your child should feel well enough to join in normal activities.
  6. 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.
  7. 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 (if age less than 2 years)
    • 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: 07/21/2023

Last Revised: 12/30/2022

Copyright 2000-2023. Schmitt Pediatric Guidelines LLC.

What to Know and When to Worry

A pediatric infectious diseases expert explains how parents can best treat a fever in young kids and when it’s time to seek care.

With many different viruses circulating this winter, parents and caregivers may begin to worry as soon as they see the first sign of a runny nose or sore throat in their children. Is it RSV? COVID-19? The flu? But the symptom that usually makes parents most concerned is fever.

“Fever is one of the most common reasons parents call the pediatrician, and when we see an increase in infections, we see more fevers,” said Dr. Karen Acker, a pediatric infectious diseases specialist and hospital epidemiologist at NewYork-Presbyterian Komansky Children’s Hospital and assistant professor of clinical pediatrics at Weill Cornell Medicine.

According to Dr. Acker, a fever, which is defined as a body temperature of more than 100.4° F, is a body’s normal response to fighting an illness. It means the immune system is doing its job, and in most circumstances there is no need to be worried.

Health Matters spoke to Dr. Acker to learn more about fevers, including how long they last, ways to treat them, and when parents need to seek medical care for their children.

Health Matters: What are important things a parent should know when their child has a fever?
Dr. Acker: Typically, a fever due to a run-of-the-mill virus can last from 24 hours to three to four days. Sometimes, fevers can last longer — even over a week — and it’s not necessarily a reason to be alarmed, as long as the child is not struggling with other symptoms, such as dehydration, shortness of breath, or severe lethargy or irritability. But if your child has prolonged fever for seven days or more, it is a good idea to bring your child to your pediatrician for evaluation.

It’s a myth that these typical fevers can cause brain damage.

If a child has symptoms such as shortness of breath, fast breathing, poor oral intake of fluids, fever of more than 104° F, then it’s important to see a pediatrician. When babies have difficulty breathing, it’s harder for them to breastfeed or drink from a bottle, and that puts them at risk for becoming dehydrated.

How do you know the fever is due to a common cold, RSV, the flu, or COVID-19?
These viruses can often look alike, and while there are some general differences, the only way to know for sure is to bring your child to the pediatrician to get tested. Influenza is typically accompanied by high fever (103° or 104° F), body aches, fatigue, and upper respiratory symptoms, including cough. RSV usually causes runny nose and cough, but children can get a fever, and 20% to 30% of children have faster breathing due to infection of the lower airways (known as bronchiolitis). COVID-19 can cause runny nose, cough, and fever, but it appears to be a less common cause of more severe disease and hospitalization in children compared to RSV and influenza. (For more, see symptoms chart below.)

When is it time to take your child to the emergency department?
That’s always the big question.

For infants less than 6 weeks old, a fever always warrants a visit to the emergency department, because young babies are at higher risk for infection. You can call your pediatrician and they will recommend going to the emergency room.

For older infants, you should discuss with your pediatrician. The pediatrician should always have an on-call service.

If your child is unable to drink, is dehydrated (has less than five wet diapers in 24 hours), has difficulty breathing, or if your baby is inconsolable, it is recommended to go to the emergency department.

How can parents treat fevers at home?
Treating a fever is more about treating the symptoms rather than trying to bring down the temperature.

If a child has a fever and is still playing, drinking fluid, eating, and running around, there is no need to treat it with medication.

However, it’s normal for children to feel really uncomfortable when they have a fever. Typical symptoms include feeling achy, having chills, or a headache. Over-the-counter fever reducers, such as acetaminophen (Tylenol) and ibuprofen (Advil, Motrin), can reduce a child’s temperature and help them feel better.

Remember, babies under 6 months cannot take ibuprofen – only acetaminophen.

You don’t need to give your child a cold bath (unless it makes your child feel better).

Many people believe an ice-cold bath is the answer to a fever. The truth is, that will only make your child really upset, and after the bath, the fever will go right back up again. If your child wants to take a bath, lukewarm water does gently reduce the body heat.

Can you explain what causes a febrile seizure?
We are still learning why a fever can trigger seizure activity in the brain and why certain children have febrile seizures, although it is likely due to a mix of genetic and environmental factors. For parents, it is really scary to witness, but fortunately febrile seizures are almost always benign. If your child has a seizure at the same time as a fever, you should go to the emergency room for evaluation to make sure it is a simple febrile seizure. If it is just one isolated seizure that lasts less than 15 minutes (simple febrile seizure), it will likely have no lasting effects on the brain, and it will not increase the risk for epilepsy. If there is more than one seizure in a 24-hour period or a prolonged seizure, your child may be observed for longer and be evaluated by a neurologist.

Does a fever mean a child is contagious?
Usually children with viral infections are the most contagious when they have a fever. That’s why schools have specific guidelines about kids needing to be fever-free, without medication, for a full 24 hours before returning to the classroom.

What foods or drinks are recommended when a child has a virus?
The main priority is good hydration, so make sure your child is drinking plenty of fluids. When children have a fever, they usually don’t hydrate as well. I tell parents to monitor how much the child is urinating. It’s easy with a baby because you can check the diapers, and you want at least five wet diapers in a 24-hour period. For older kids, urinating every six hours is normal.

They are probably not going to have a big appetite, and that’s OK. If your child has vomiting and diarrhea, it’s best to choose foods that are not too hard on the stomach, such as applesauce, rice, and toast. And, of course, chicken soup, which has the added benefit of helping with hydration. Parents also ask about vitamin C or zinc to fight infection. If your child has a balanced diet, they are getting the appropriate amounts of vitamin C and zinc, so supplementation is not generally recommended or thought to have any impact.

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Fever in children – NCCH

36. 6˚ is the average normal body temperature for an adult. In children, the average body temperature is 0.3-0.4˚ C higher than in adults. In addition, the temperature in children is characterized by significant lability and its average fluctuations in newborns can be about 0.4 ° C, and in older children up to 1 ° C. Factors such as food intake, hunger, movement, anxiety, change of sleep and wakefulness affect the temperature. It must be remembered that there are daily fluctuations in temperature, in the evening it is usually slightly higher. In young children with insufficient maturity of thermoregulation processes, environmental factors have a significant impact, it is important to remember that children are very easy to both overcool and overheat, so the air temperature in the room, the quantity and quality of clothes on the child, etc. are important. If the child seemed hot to you, and you decided to measure the temperature, you must wait 15-20 minutes after sleep or physical activity, uncover the child. The temperature should not be measured in the hands of the mother, but in a calmly sitting or lying child. When measuring the temperature in the armpit, you just need to hold the child’s hand with a thermometer with your hand or use an ear infrared thermometer.

Fever is an increase in body temperature ≥38˚ C, in most cases it is not dangerous, it is a normal physiological reaction of the body to infectious and non-infectious diseases. In young children, febrile illnesses are common and are usually caused by viral infections.

In the body, the role of the thermoregulation center is performed by the hypothalamus, the mechanism of its action is based on achieving a balance between heat production and heat loss.

Febrile convulsions are genetically determined, develop in 3-4% of children, as a rule, are not accompanied by epileptic activity of the brain, do not affect the further development of the child and do not recur after 6 years. In almost 50% of cases, febrile convulsions are single, however, if they are present in the history of the child, antipyretics are recommended for him at lower fever figures.

Of course, one can understand the excitement of parents and grandparents when a child has a fever, but they need to remember that by lowering the temperature, especially low values, they calm themselves more than help the child. So, in most viral infections, only during an increase in temperature, antibodies to the virus and various active substances are produced that are responsible for the immune response and immunological memory. Therefore, an artificial decrease in temperature can lengthen the period of the disease. If a child has started antibiotic therapy for a bacterial infection, it is important to evaluate the effectiveness of the antibiotic, which can be seen primarily by self-reduction of body temperature. Against the background of antipyretics, this is quite difficult to do, and the sooner the child receives the correct treatment, the lower the risk of possible complications. Taking into account all of the above, international recommendations have been developed for the appointment of antipyretics. They are indicated in initially healthy children under the age of 3 months with an increase in body temperature above 38 °C. For children older than 3 months, antipyretics are prescribed at a temperature above 39-39.5˚С. For children at risk (with congenital heart defects, diseases of the central nervous system, etc.), as well as with previously identified febrile convulsions, the temperature is reduced to a lower temperature – 37.5-38 ° C. If the child feels unwell with a fever, refuses to eat and drink, parents can begin to lower the temperature to a lower temperature. No guideline for the management of children with fever recommends the use of antipyretics solely to reduce fever.

Temperature reduction is carried out by physical cooling methods and, if necessary, medication. If the child does not have chills, marbling of the skin, the room should be ventilated, the child is open. With cold hands and feet, they must be rubbed to redness or given a no-shpu in order to expand the peripheral vessels for an adequate heat transfer process. The drugs of choice among antipyretics for children are paracetamol and ibuprofen with many convenient dosage forms for the child. A single dose is calculated on body weight and is 10-15 mg / kg (every 6 hours, if necessary) for paracetamol and 5-10 mg / kg (every 6 hours, if necessary) for ibuprofen. If the dose of antipyretics is insufficient, the effect of them may not be. In the presence of vomiting, the form in candles is convenient. A decrease in temperature, as a rule, can be expected 30-60 minutes after taking the drug (somewhat longer with rectal use) and the effect lasts up to 3-8 hours. If the temperature is very high, physical cooling methods can be used until the antipyretic begins to take effect or until the time of the next dose of the drug. Vinegar and vodka, when rubbed, can have both a local irritant effect and a toxic effect when absorbed through the skin. Therefore, the simplest and safest way is to wipe the child with ordinary water at 25-30˚ C. It is necessary to wipe the neck, back of the head, inguinal and axillary folds, forehead, and then other surfaces.

It is not recommended to alternate paracetamol and ibuprofen, as well as to give their combined preparations, this combination is no more effective than monotherapy, but is fraught with serious side effects and can lead to acute renal failure. Also, nimesulide, acetylsalicylic acid preparations are not used in children with an antipyretic purpose, and metamizole (analgin) can only be administered intramuscularly in order to quickly reduce the temperature. All of these drugs can cause serious side effects that are incomparable to their antipyretic effect.

Usually a decrease in temperature by 0.5-1˚ C is sufficient to improve the child’s well-being, it is not necessary to achieve a decrease in temperature to normal numbers. Large diurnal fluctuations in temperature may have a more significant negative effect than the fever itself.

We have already said above that fever in children is most often accompanied by acute infectious diseases, which can be of both viral and bacterial etiology. In the vast majority of cases, a viral infection does not require the appointment of an antibiotic (antibiotics do not act on viruses), children are treated with symptomatic agents and, if necessary, reduce the temperature. In the case of a proven bacterial etiology of the disease, it is necessary to prescribe antibiotic therapy. It is up to the doctor to decide what exactly the child is sick with, and, accordingly, how to treat him. However, if the disease begins with fever, runny nose and cough, the child’s condition suffers slightly, with a high degree of probability one can think about the development of a respiratory viral infection and treat the child symptomatically. If the temperature persists for more than 3 days, of course, it is necessary to consult a doctor, control a blood test, if urine is needed, with a decision on the advisability of prescribing an antibiotic. A disease that is not accompanied by catarrhal symptoms, a runny nose, should be more alert to both parents and doctors, due to the higher likelihood of any bacterial infection that needs to be diagnosed and treated in time. Although some viral infections, such as enterovirus, can also occur without any symptoms other than high fever.

Remember that antipyretics are also drugs! They have their side effects! In addition, the imaginary improvement in the child’s well-being against the background of antipyretics should not be a reason for refusing timely examination by a pediatrician and prescribing the necessary treatment.

Clinical recommendations for acute respiratory viral infections – GBUZ BGDB No. 1

Clinical guidelines:

“Acute respiratory viral infection (ARVI) in children. ICD 10: J00 / J02.9 / J04.0 / J04.1 / J04.2 / J06.0 / J06.9

Year of approval (revision frequency): 2018 (revision every 3 years)

Professional associations: Union of Pediatricians of Russia

Approved by: Union of Pediatricians of Russia

Appendix B. Information for patients

SARS (acute respiratory virus) infection) is the most common disease in children.

The cause of the disease is a variety of viruses. The disease often develops in autumn, winter and early spring.

How they become infected with an infection that causes SARS: most often by getting on the nasal mucosa or conjunctiva from hands contaminated by contact with the patient (for example, through a handshake) or with surfaces infected with the virus (rhinovirus persists on them for up to a day).

Other way – airborne – by inhalation of saliva particles released when sneezing, coughing or in close contact with the patient.

Period from infection to onset of illness: in most cases 2 to 7 days. Isolation of viruses by patients (infectiousness for others) is maximum on the 3rd day after infection, sharply decreases by the 5th day; mild shedding of the virus can persist for up to 2 weeks.

Signs of ARVI: the most common manifestation of ARVI in children is nasal congestion, as well as nasal discharge: transparent and / or white and / or yellow and / or green (yellow or green nasal discharge is not a sign of a bacterial infection!). An increase in temperature often lasts no more than 3 days, then the body temperature decreases. In some infections (influenza and adenovirus infection), the temperature above 38? C persists for a longer time (up to 5-7 days).

SARS may also cause: sore throat, cough, red eyes, sneezing.

Examinations: in most cases, additional examinations are not required for a child with SARS.

Treatment: SARS, in most cases, is benign, resolves within 10 days and does not always require medication.

Decrease in temperature: a feverish child should be opened, wiped with water T° 25-30°C. In order to reduce the temperature in children, it is permissible to use only 2 drugs – paracetamol or ibuprofen. Antipyretic drugs in healthy children ≥3 months are justified at temperatures above 39- 39.5°C. With a less pronounced fever (38-38.5 ° C), fever-reducing agents are indicated for children under 3 months old, patients with chronic pathology, as well as temperature-related discomfort. Regular (course) intake of antipyretics is undesirable, a second dose is administered only after a new increase in temperature.

The alternation of these two drugs or their use in combination does not lead to an increase in the antipyretic effect.

Do not use acetylsalicylic acid and nimesulide for antipyretic purposes in children. It is highly undesirable to use metamizole in children due to the high risk of developing agranulocytosis. In many countries of the world, metamizole has been banned for use for over 50 years.

Antibiotics – do not work against viruses (the main cause of SARS). Antibiotics are considered if a bacterial infection is suspected. Antibiotics must be prescribed by a doctor. Uncontrolled use of antibiotics can promote the development of resistant microbes and cause complications.

How to prevent the development of SARS:

A sick child should be left at home (do not take to kindergarten or school). Of paramount importance are measures to prevent the spread of viruses: thorough hand washing after contact with the sick.