Causes of fever in newborns

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.

Bellevue
Everett
Federal Way
Seattle

Care Advice for Fever

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.
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.
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.
Give an acetaminophen product (such as Tylenol).
Another choice is an ibuprofen product (such as Advil) if over 6 months old.
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.
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.
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.
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: 10/17/2022

Last Revised: 09/18/2022

Fevers in Infants Under 3 Months > Fact Sheets > Yale Medicine

Overview

When your baby spikes a fever, you can't help but worry. A fever—or febrile illness—in infants is something to see a pediatrician about right away because it is the most common sign of childhood illness.

Since infants with their still-developing immune systems are so vulnerable to infection, most fevers (above 100.4 degrees Fahrenheit) experienced during the first three months of life are taken seriously by pediatricians and emergency medicine doctors alike.

Illnesses that bring on fevers in infants are usually caused by viral infections, but about 10 percent are caused by potentially more serious bacterial infections, says Paul L. Aronson, MD, a Yale Medicine pediatric emergency specialist. These can include urinary tract infections, blood infections or bacterial meningitis—an infection of the fluid surrounding the brain and spinal cord.

Our experts are actively investigating ways to improve how infants with fevers are treated. Yale New Haven Children's Hospital is joining other hospitals around the country in an effort to determine the best way to treat this age group when they experience a fever.

What are the symptoms of infant febrile illness?

If an infant in the first 90 days of life has a temperature of 100.4 degrees Fahrenheit or above (optimally taken rectally for accuracy), a pediatrician should be consulted immediately. Older babies and children should also receive medical attention when needed for fevers, too.

Examination may lead a pediatrician to find, for example, an ear infection (otitis media), pneumonia, tonsillitis or gastroenteritis, among other illnesses.

Unlike adults or older children, some infants might not have any other symptoms except for the fever. But other symptoms of illness or infection can include:

fussiness
a change in feeding behavior
sleepiness/difficulty waking up

If the fever is caused by a virus, it might be accompanied by a runny nose, sneezing and/or coughing. These symptoms may also be present with a serious bacterial infection, and a pediatrician can decide if emergency care is warranted.

What are the risk factors for infant febrile illness?

Young infants with infections commonly have fever as a symptom. Premature babies, infants with chronic illnesses (such as heart disease), and babies born to mothers who have a bacterial infection (such as group B strep) are at an increased risk of having a fever due to a serious bacterial infection.

Sometimes young children who get fevers will experience febrile convulsions are seizures (fits or convulsions) without another underlying cause. Children who experience febrile seizures should receive immediate medical attention.

How is infection diagnosed in infants with febrile illness?

The diagnosis is made with a clinical examination and laboratory testing. “We observe how the baby looks overall,” says Dr. Aronson.

“We get aggressive with our diagnostic tests and treatment if the baby looks ill, but even if the baby looks well, laboratory testing is necessary to evaluate for a bacterial infection.” A urine test and blood test will probably be taken right away.

While bacterial cultures are the definitive tests used to diagnose a serious bacterial infection, it may take a day or two before the results are known. Therefore clinicians rely on the baby’s medical history, appearance and results of more rapidly available urine and blood tests to determine if the baby might have a more serious bacterial infection.

A spinal tap may also need to be performed to evaluate for meningitis if the baby is very young (less than one month of age) or if he or she has other concerning signs or symptoms, or abnormalities in initial blood testing.

“A spinal tap understandably causes parents the most anxiety,” Dr. Aronson says. “It involves drawing fluid through a tiny puncture in the baby’s lower back with a small needle.” Spinal fluid is obtained below the level of the actual spinal cord, so there is a low risk of damaging the spinal cord, he says. “There are risks of introducing an infection or bleeding with the procedure, but these risks are also very low.”

If bacterial meningitis goes undetected and/or untreated, it can cause neurologic damage, hearing loss, kidney failure, seizures, learning disabilities or even death.

How is infant febrile illness treated?

Infants one month old or younger would likely be admitted to the hospital to receive antibiotics for 24 to 48 hours. It might take hours or days to get results from a urine, blood or spinal fluid bacterial culture, which is why many infants are treated with antibiotics immediately, even if a diagnosis is not yet conclusive.

Some babies older than one month might be sent home without antibiotics if the baby looks well and has reassuring results of the laboratory testing available in the emergency department. Families with infants discharged from the emergency department should follow up with their pediatrician the next day.

If there is concern about bacterial infection, babies may be admitted to the hospital to be treated with antibiotics. If antibiotics are started early, the outcomes for infants with bacterial infection are good.

If no bacterial infection is found, a baby will continue to be monitored, either in the hospital or at home, to make sure that any viral infections are clearing up on their own.

What makes Yale Medicine's approach to infant febrile illness unique?

“The research I’m involved with seeks to improve strategies for caring for young infants with fevers,” Dr. Aronson says. “Because serious infections are rare yet dangerous, the key is to figure out how not to under- or over-treat babies. By identifying infants at both high and low risk for bacterial infection, we hope to better target testing and antibiotics to those infants most vulnerable," he says.

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, restlessness, alternation of sleep and wakefulness. 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.

types, symptoms, diagnosis, treatment, clinical recommendations

Fever is insidious in that it may not threaten anything, or may be a symptom of a transient dangerous infection. When the temperature rises, you should understand the possible cause and constantly monitor the changes.

Heat exchange in children is somewhat different than in adults. At birth, all babies have a special brown fat, which quickly disappears, being replaced by ordinary white fatty tissue.

Brown fat contains many mitochondria. They oxidize fatty acids and release heat when needed. Since babies are very vulnerable in the first days of life, this mechanism protects them from hypothermia.

In the process of life, the mechanisms of heat transfer in children continue to form and become more and more similar to the thermoregulation of adults. In fact, the final development of the system ends only by 8 years. Until this age, children lose heat worse, and at the same time they produce it better. Because of this, overheating is more dangerous for the baby, and the entire thermoregulation system is much more unstable. Temperature jumps in children happen often, and the reasons can be very different.

What is fever

Body temperature above 37 ° C is considered hyperthermia, that is, fever. When measuring temperature in the rectum, fever is considered to be above 38 ° C.

The mechanism of the occurrence of fever is as follows: under the action of pyrogens - substances that stimulate an increase in temperature, the release of anti-inflammatory substances is stimulated. Pyrogens are most often of an infectious nature. They act on the thermoregulatory center, which becomes less sensitive to thermal impulses. The entire thermoregulation system is rebuilt to work at a higher level. That is, heat production increases and heat transfer decreases, which leads to a general increase in body temperature.

At the same time, many viruses and bacteria in such a "heat" reduce the rate of reproduction, and the immune system increases the synthesis of antibodies. The activity of leukocytes, inflammatory cells, also increases. At its core, an increase in temperature is a protective reaction of the body, this allows you to quickly defeat the infection and activate the immune system.

Symptoms of fever in children

An increase in body temperature immediately affects the well-being of the child. The skin becomes hot, wet, the baby complains of weakness, chills, headache, cries. If the fever is severe, then delirium, confusion and convulsions are possible.

Clinically, fever in children is divided into "pink" and "pale".

The most common is "pink", relatively harmless. It is provoked mainly by infections, and the child feels quite well, despite the high numbers on the thermometer. At the same time, the baby's skin is red, hot, moist, legs and arms remain warm. The higher the temperature, the more often the child begins to breathe, the pulse quickens.

Pale fever is much more dangerous. Due to vasospasm, the skin becomes pale, may be covered with "marble" cyanotic spots. The skin is hot, but dry, the child hardly sweats. Hands and feet are cold, shortness of breath may begin. There are problems with pressure - it rises sharply, and then can drop almost to a state of shock. At the same time, the child is excessively lethargic, it is impossible to wake him up; or, on the contrary, overexcited, he is disturbed by hallucinations and delirium.

Pale fever is characteristic of severe bacterial infections. It requires special attention, as it can cause serious complications.

Causes of fever in children

The body temperature of young children is very unstable. It can fluctuate from emotional overexcitation, fatigue. At an older age, hormonal failure during puberty can also cause fever.

But the main causes are various infections, they account for up to 80% of all cases of fever. Injuries, internal hemorrhages, burns and bruises, overheating in the sun and dehydration can also cause fever. The reasons can be very serious: tumors, genetic diseases, hormonal disorders.

Fever is usually accompanied by a sharp short rise in temperature, which is stopped by drugs and lasts for several hours or even weeks. There are long-term conditions, while the temperature rises slightly, but often. One such example is thermoneurosis. To determine the exact cause, you need to call a pediatrician.

Treatment of fever in children

Almost always the body temperature rises as a reaction to an infection: bacteria, viruses. Some of these diseases have few specific symptoms early on, such as meningococcal disease. At the same time, these diseases develop rapidly and can lead to death, so you should always pay increased attention to fever.

Treatment will be specific, aimed at eliminating the cause - the focus of infection. For this, antibiotics, antiviral drugs, as well as their own immunity forces are used. To reduce the temperature with threatening numbers, antipyretics are used in various forms. Dosage and choice of drug depend on the age of the child.

A slight and short-term increase in temperature may be associated with nervous tension, overheating, teething. It is important to know that the very fact of teething cannot cause a significant rise in temperature - normally, this process is quite natural and does not cause fever. If teeth are cut, and the temperature rises very much, the reason is almost certainly not in the teeth, and you should not relax.

You need to find the cause, think about what happened before the temperature rise that could cause the fever. If it is overheating, the child needs to be moved to a cool place, give water, cool his head, wipe his body with water, direct a fan at the baby. Do not wipe the skin with pure alcohol, vodka, or too cold water and ice. Too much cold constricts the blood vessels of the skin, and heat transfer decreases even more, the body cannot cool. And alcohol can be partially absorbed through the skin, and its vapors also adversely affect the baby.

It is important to ensure adequate fluid intake. The temperature can drop badly from dehydration, so sometimes you even have to force a sick child to drink. There is a special formula, according to which, with each degree of excess temperature, the volume of liquid that needs to be taken increases. For every degree of elevated temperature, 10 ml of water per kilogram of the child's weight is added.

Photo: @karolina-grabowska, pexels.com

Diagnostics

Various thermometers, including mercury and electronic, are used to measure temperature. The latter are not very accurate, and the error in degrees can be large. Mercury thermometers must be used very carefully so as not to break it.

Temperature in children is taken under the armpit, in the groin or in the rectum. To measure on the surface of the skin, the fold must be wiped with a towel, and wait for the skin to dry. Shake the thermometer to 35 °C, wipe it with a disinfectant and insert it into the armpit or into the skin fold in the groin. You need to hold the thermometer by pressing the bent arm or leg of the child for about 10 minutes.

The most accurate method is in the rectum, in children under 2 years old this is the main method. Rectal temperature is always higher than on the surface of the body. Normal rectal temperature is considered to be 37.3-37.7. Before the measurement, it will not be superfluous to do a cleansing enema, but you can do without it. Before measuring, disinfect the thermometer as well, lubricate the tip with petroleum jelly and insert into the rectum to a depth of no more than 5 centimeters. Then squeeze the buttocks with your hands and hold for about 5 minutes.

Modern methods of treatment

The most effective way to overcome a fever urgently is to take antipyretic drugs. They are also called antipyretics.

It is not necessary to give such medicines at every jump in temperature, and even more so as a preventive measure - it will not work. Usually, antipyretics are used after 38 - 39 ° C, before this threshold the child feels quite well, and a slight fever helps to cope with the disease.

When convulsions appear, under the age of 2 months, if you feel very unwell, you need to focus on the child's feelings, and not on a thermometer. Sometimes antipyretics are required with a slight increase in temperature, and sometimes more than 39°C is well tolerated by the child.

The fever should subside within about half an hour after taking the drug. If the antipyretic in the form of tablets, gels and syrups was ineffective, intramuscular or intravenous injections are usually administered. Persistent fever, which is not stopped for a long time by drugs, is the reason for calling an ambulance. Hospitalization may be required.

Photo: pixabay.com

Prevention of fever in children at home

With any infectious disease, an increase in temperature is possible. It's impossible to avoid it. You just need to monitor the condition of the child, do not wrap him in blankets too much, give him enough liquid.

When the fever subsides, there will be active sweating, all clothes and bedding may become wet. To make your child more comfortable and avoid catching a cold, change your underwear more often.

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