Fever in Children: Causes, Symptoms, and Treatment

What is Fever in Children?

A fever in children is a temporary increase in body temperature, often due to an illness. A child has a fever when their temperature is at or above one of these levels:

• 100.4°F (38°C) measured in the bottom (rectally)
• 99.5°F (37.5°C) measured in the mouth (orally)
• 99°F (37.2°C) measured under the arm (axillary)

Fever itself is not an illness—it’s usually a sign that the body is fighting an infection. Most fevers in children are caused by viral infections and are not dangerous. However, fevers can also indicate more serious conditions that require medical attention.

Source: Mayo Clinic, CDC

Common Causes

Fever in children can be caused by a variety of conditions, including:

• Viral infections: The most common cause of fever in children. Examples include the common cold, flu (influenza), roseola, and respiratory syncytial virus (RSV).
• Bacterial infections: Such as ear infections, urinary tract infections (UTIs), strep throat, or bacterial pneumonia.
• Immunizations: Some vaccines, like the DTaP or pneumococcal vaccine, can cause a mild fever as a side effect.
• Teething: While teething may cause a slight increase in temperature, it’s not usually the cause of a high fever.
• Heat exhaustion or heatstroke: Prolonged exposure to high temperatures can raise body temperature.
• Inflammatory conditions: Such as juvenile idiopathic arthritis or Kawasaki disease.
• Serious infections: Like meningitis (infection of the membranes around the brain and spinal cord) or sepsis (a severe bloodstream infection).
• Autoimmune disorders: Such as lupus, which can cause recurrent fevers.
• Cancer: In rare cases, fevers can be a sign of childhood cancers like leukemia.
• Other illnesses: Such as malaria (in endemic areas) or COVID-19.

Source: NHS, Johns Hopkins Medicine

Associated Symptoms

Fever in children is often accompanied by other symptoms, which can help identify the underlying cause. These may include:

• Sweating or chills
• Headache or body aches
• Fatigue or irritability
• Loss of appetite
• Dehydration (dry mouth, fewer wet diapers, or sunken eyes)
• Rash (could indicate conditions like roseola or measles)
• Cough or sore throat
• Nausea, vomiting, or diarrhea
• Stiff neck (a potential sign of meningitis)
• Difficulty breathing or rapid breathing

If your child has a fever along with any of these symptoms, it’s important to monitor them closely and seek medical advice if necessary.

Source: HealthyChildren.org (AAP)

When to See a Doctor

While most fevers in children are not serious, there are times when you should contact a healthcare provider. Seek medical advice if:

• Your child is under 3 months old and has a rectal temperature of 100.4°F (38°C) or higher. This is an emergency.
• Your child is 3 to 6 months old and has a fever of 102°F (38.9°C) or higher.
• The fever lasts more than 24 hours in a child under 2 years old, or more than 3 days in a child 2 years or older.
• Your child has a fever that repeatedly rises above 104°F (40°C).
• The fever does not improve with medication or returns quickly after medication wears off.
• Your child has signs of dehydration (e.g., no tears when crying, fewer wet diapers, sunken soft spot on the head).
• Your child has a seizure (febrile seizure).
• Your child has a weakened immune system (e.g., from chemotherapy or chronic illness).
• Your child has other concerning symptoms, such as a rash, stiff neck, severe headache, difficulty breathing, or persistent vomiting.

When in doubt, it’s always best to contact your pediatrician for guidance.

Source: Cleveland Clinic

Diagnosis

To diagnose the cause of a fever, a healthcare provider will typically:

• Take a medical history: Ask about symptoms, duration of the fever, recent illnesses, vaccinations, and exposure to sick individuals.
• Perform a physical exam: Check for signs of infection (e.g., ear infection, sore throat, rash) and assess overall health.
• Measure temperature: Confirm the fever using a reliable thermometer.
• Order tests if needed:
  • Blood tests (e.g., complete blood count or cultures)
  • Urinalysis (to check for UTIs)
  • Chest X-ray (if pneumonia is suspected)
  • Lumbar puncture (spinal tap) (if meningitis is suspected)
  • COVID-19 or flu testing (if symptoms suggest these illnesses)

In many cases, no specific testing is needed, and the fever resolves on its own as the body fights off the infection.

Source: UpToDate

Treatment Options

Treatment for fever in children focuses on relieving discomfort and addressing the underlying cause. Here are the options:

Medical Treatments

• Acetaminophen (Tylenol): Safe for all ages (follow dosing instructions based on weight).
• Ibuprofen (Advil, Motrin): Safe for children over 6 months old (avoid in dehydrated children).
• Avoid aspirin: Never give aspirin to children due to the risk of Reye’s syndrome.
• Antibiotics: Only used if a bacterial infection (e.g., strep throat, UTI) is confirmed.
• Antivirals: May be prescribed for flu or COVID-19 in high-risk children.

Home Remedies

• Hydration: Encourage fluids like water, breast milk, or electrolyte solutions (e.g., Pedialyte) to prevent dehydration.
• Rest: Let your child rest to help their body recover.
• Light clothing: Dress your child in lightweight clothing and avoid bundling them up.
• Lukewarm bath: A sponge bath in lukewarm water can help reduce fever (avoid cold water or alcohol rubs).
• Cool compress: Place a cool, damp cloth on your child’s forehead or neck.

Note: Fever-reducing medications are not always necessary. If your child is comfortable and hydrated, you may not need to treat the fever itself.

Source: American Academy of Pediatrics (AAP)

Prevention Tips

While not all fevers can be prevented, you can reduce your child’s risk by:

• Handwashing: Teach your child to wash their hands frequently with soap and water.
• Vaccinations: Keep your child up to date on recommended vaccines (e.g., flu shot, MMR, pneumococcal).
• Avoiding sick contacts: Limit exposure to people who are ill, especially during flu season.
• Breastfeeding: If possible, breastfeed infants to boost their immune system.
• Healthy diet: Provide a balanced diet rich in fruits, vegetables, and whole grains.
• Hydration: Ensure your child drinks plenty of fluids daily.
• Clean environment: Regularly disinfect surfaces and toys, especially in daycare settings.

Source: World Health Organization (WHO)

Emergency Warning Signs

Seek emergency medical care immediately if your child has a fever and any of the following:

• Difficulty breathing or breathing very fast.
• Blue lips, tongue, or skin (sign of low oxygen).
• Seizure (convulsion) or uncontrolled shaking.
• Extreme lethargy (difficulty waking up or not responding).
• Stiff neck or severe headache (possible meningitis).
• Rash that does not fade when pressed (could indicate a serious infection like meningococcemia).
• Refusal to drink or signs of severe dehydration (e.g., no urine for 8+ hours).
• Persistent vomiting or inability to keep fluids down.
• Fever over 104°F (40°C) that does not improve with medication.

If your child shows any of these signs, call 911 or go to the nearest emergency room.

Source: CDC, Mayo Clinic