By Dr. Pothireddy Surendranath Reddy
Introduction

Fever in children is one of the commonest causes for concern among parents and caregivers. A child with a raised body temperature can trigger anxiety, but it is critical to understand that fever is often a normal, protective physiological response to infection. In pediatric practice, managing fever requires balancing comfort and safety, avoiding overtreatment, and recognizing signs that point to more serious illness.
In this comprehensive analysis, I explain what fever is in children, why it happens, how to evaluate it, when to worry, how to treat it, and preventive strategies. My goal is to provide guidance to both parents and clinicians, emphasizing evidence-based care and practical decision-making.
1. What Is Fever in Children?
- Fever (or pyrexia) means a core body temperature higher than normal. In children, a commonly accepted threshold for a high temperature is 38 °C (100.4 °F). nhs.uk
- It’s important to use a digital thermometer for accuracy. For younger children, axillary (underarm) readings are often used; for older children, oral or tympanic (ear) measurements may be appropriate. NHS Nottingham and Nottinghamshire ICB+1
- A mild fever lasting 1 to 4 days is very common in children, especially with viral infections. nhs.uk+1
- In children under 5 years, there are established guidelines (such as those from NICE) for the assessment, risk stratification, and early management of fever with no obvious source. Nice+1
2. Why Fever Occurs: Pathophysiology
Fever arises when pyrogens (which may be produced by the body or come from infecting organisms) act on the hypothalamus, raising the body’s “thermostat.” Key cytokines — such as interleukin-1 (IL-1), IL-6, and tumor necrosis factor-alpha (TNF-α) — mediate this response.
Benefits of fever:
- Enhances immune cell activity.
- Limits replication of certain pathogens that prefer lower temperatures.
- Signals to caregivers that something is happening, prompting care or evaluation.
Risks if untreated or mismanaged:
- Dehydration, especially in young children who may refuse fluids.
- Febrile seizures in children predisposed to them (typically 6 months to 5 years).
- In rare cases, underlying serious bacterial infection.
3. Common Causes of Fever in Children
Fever in children has a wide differential. Most causes are benign, but clinicians must remain vigilant.
A. Infectious Causes
- Viral Infections
- Most fevers in children are caused by viruses — common cold viruses, influenza, respiratory syncytial virus (RSV), adenovirus, enteroviruses. nth.nhs.uk
- Often self-limiting and resolve without specific antiviral therapy.
- Bacterial Infections
- These can include urinary tract infections (UTIs), ear infections (otitis media), pneumonia, meningitis, and more serious systemic infections (e.g., septicemia). NHS Inform+1
- Bacterial infections may require antibiotics once identified.
- Post-Immunization Fever
- Fever sometimes occurs in children after vaccination (up to ~48 hours) and typically resolves spontaneously. rhc.nhsggc.org.uk
- Other Infectious Causes
- Less common but important: urinary tract infections, especially in young children, necessitating urine testing. Royal Children’s Hospital
- Localized infections (skin, throat) or deeper infections (abscesses) may also present with fever.
B. Non-Infectious Causes
- Inflammatory or Autoimmune Disorders
- Conditions like juvenile idiopathic arthritis, vasculitis, or systemic lupus can present with fever.
- Drug-related Fever
- Some medications trigger fever as a side effect.
- Other Causes
- Rare conditions such as malignancies, periodic fever syndromes; also heat exposure may elevate temperature.
4. Clinical Evaluation: What to Do When a Child Has a Fever
4.1 History Taking
When a child presents with fever, key information includes:
- Onset, duration, and pattern of fever.
- Associated symptoms: cough, vomiting, diarrhea, ear pain, rash, irritability, feeding reduction.
- Fluid intake and urine output (wet diapers).
- Recent immunizations.
- Exposure history: sick contacts, travel, insect bites.
- Medical history: underlying chronic illness, immunocompromise.
4.2 Physical Examination
A complete pediatric exam should include:
- Measurement of temperature using a reliable thermometer.
- Hydration status: dry lips, sunken eyes, capillary refill.
- Signs of respiratory infection: listening to lungs, nasal congestion.
- Neurological signs: irritability, lethargy, neck stiffness (meningitis risk).
- Skin: rashes, petechiae, signs of dehydration.
4.3 Risk Stratification Using Guidelines
In children under 5, clinicians often use traffic-light systems or guidelines (e.g., NICE NG143) to decide which children require further investigation or urgent referral. Nice
These guidelines help decide risk of serious illness (like sepsis) and whether to do urine tests, blood tests, or refer for admission.
4.4 Investigations
Depending on the clinical picture, investigations may include:
- Complete blood count (CBC), C-reactive protein (CRP), or procalcitonin (if available) to assess inflammation.
- Urinalysis and urine culture: especially important in unexplained fever, urinary symptoms, or in infants with no obvious source. Royal Children’s Hospital
- Blood cultures, if there is suspicion of bacteremia or sepsis.
- Chest X-ray, if respiratory signs present.
- Lumbar puncture, if there is suspicion of meningitis (neck stiffness, altered sensorium).
- Additional tests: depending on age and risk, e.g., viral panels, nasopharyngeal swabs, or diagnostic imaging.
5. When to Seek Medical Help: Parental Red Flags
Certain features in a feverish child should prompt urgent medical evaluation:
- Age < 3 months with a temperature ≥ 38°C — requires prompt medical assessment. nth.nhs.uk
- Prolonged fever: if fever persists > 5 days (some sources say 3–5 days), especially in very young children. nhs.uk
- Signs of dehydration: reduced urine output, dry mouth, sunken eyes. nbt.nhs.uk
- Febrile seizures: convulsions associated with fever — though often benign, require medical evaluation. gloshospitals.nhs.uk+1
- Rash that doesn’t blanch (i.e., pressing against skin doesn’t make it fade) — possible meningococcal disease. nhs.uk
- Difficulty breathing, lethargy, persistent vomiting, or any sign that child “looks sicker than usual.” nbt.nhs.uk
6. Home Management of Fever in Children
When the child is alert, drinking, and not severely ill, much can be done at home to safely manage fever and comfort the child.
6.1 Comfort Measures
- Hydration
- Encourage frequent fluids: water, diluted juice, oral rehydration solutions if needed.
- For infants, continue breastfeeding/on-demand feeds.
- Clothing and Environment
- Dress child in light, breathable clothing; avoid over-wrapping. nth.nhs.uk
- Keep the room at a comfortable temperature; avoid cold sponging as it can cause shivering, which paradoxically raises body temperature. nth.nhs.uk+1
- Rest
- Allow the child to rest, but encourage normal activity as tolerated.
6.2 Use of Antipyretic Medicines
- Paracetamol (Acetaminophen) — given in appropriate weight-based dosing, can reduce fever and relieve discomfort.
- Ibuprofen — is also effective, but should not be used in children with dehydration, vomiting, or certain conditions unless advised by a physician. Nice
- Use one medication at a time, unless a healthcare provider has specifically advised alternating. NHS guidance warns against alternate ibuprofen and paracetamol without professional advice. nhs.uk
- Always follow the dosage instructions carefully; overdosing is a risk.
7. Clinical Management and Referral
7.1 Primary Care / Outpatient Setting
- Use risk stratification (NICE guideline NG143) to decide which children may be safely managed at home and who needs further evaluation. Nice
- For children under 5 with no obvious focus: follow the NICE traffic-light assessment to guide further investigation or admission. NCBI
- In children who are well-appearing, with mild symptoms and maintaining hydration, antibiotics are not routinely necessary. nbt.nhs.uk
- Provide clear safety-net advice to parents: when to return, what warning signs to watch, how to give antipyretics.
7.2 Emergency / Hospital Setting
Consider urgent referral or admission if:
- The child is very young (especially <3 months) and unwell.
- There are signs of sepsis, meningitis, or other serious infection. Royal Children’s Hospital
- The child is dehydrated, has persistent high fever, is lethargic, or has no improvement after 48 hours of home care. nbt.nhs.uk
In hospital, relevant investigations will be done (blood, urine, cultures), and empiric antibiotic therapy may start if serious bacterial infection is suspected.
8. Febrile Seizures
- Febrile seizures are convulsions in a child triggered by fever; they are relatively common in children between 6 months and 5 years. gloshospitals.nhs.uk
- Though frightening, simple febrile seizures (generalized, <15 minutes, no recurrence within 24 hours) generally have a benign prognosis. gloshospitals.nhs.uk
- After a seizure:
- Place the child safely (on side to prevent choking).
- Do not put anything in their mouth.
- After the seizure, seek medical advice — especially if this is the first seizure.
- Ongoing management focuses on treating the fever cause, not on preventing seizure recurrence with medications, in most cases.
9. Prevention & Parental Guidance
Preventing or reducing the risk of fever in children involves:
- Vaccination
- Ensure that children are up to date with childhood immunizations (measles, mumps, rubella, pneumococcal, influenza, etc.) to prevent infections that cause fever.
- Good Hygiene Practices
- Encourage frequent hand washing.
- Teach cough/sneeze etiquette.
- Avoid close contact with sick individuals when possible.
- Safe Environment
- Avoid overheating: dress appropriately, maintain a comfortable room temperature.
- Encourage rest and good nutrition.
- Parental Education on Fever
- Educate caregivers that fever is often a helpful, normal immune response.
- Provide clear instructions on how to measure temperature, give antipyretics, and monitor for warning signs.
- Develop a “fever care plan”: when to use medicines, when to call a doctor, how often to check fluids and general well-being.
10. Special Situations
10.1 Infants (<3 months)
- Fever in a young infant is more concerning. Even a small rise in temperature may indicate a serious infection.
- These infants often require a full sepsis workup: blood culture, lumbar puncture, empiric antibiotics. Royal Children’s Hospital
- Home measures are insufficient; immediate medical evaluation is mandatory.
10.2 Recurrent Fever Syndrome
- If a child has recurrent unexplained fevers, consider periodic fever syndromes, autoimmune disorders, or immunodeficiencies.
- Referral to a pediatric specialist or immunologist may be warranted.
11. Misconceptions About Fever
- “High fever always means serious illness” — Not necessarily. Many high fevers are due to benign viral infections. nbt.nhs.uk
- “Teething causes very high fever” — Teething may cause slight temperature rise, but very high fever usually indicates a different cause.
- “Sponge baths or cold water baths reduce core fever significantly” — Cool sponging may make the child more comfortable, but can cause shivering and may not significantly lower core temperature. nth.nhs.uk
- “Fever itself damages the brain” — There is no evidence that typical fevers (even high) in healthy children cause brain injury. They serve a purpose.
12. Prognosis
- Most fevers in children, especially when due to viral infections, resolve within 1–4 days. nhs.uk
- With correct assessment and timely intervention, serious bacterial infections can be treated effectively, and complications (like dehydration, febrile seizures) are minimized.
- Parental reassurance and proper education are crucial: unnecessary antibiotic use, panic, or over-treatment can be avoided when caregivers understand fever as a sign, not always the disease itself.
Conclusion
Fever in children is a very common and often benign sign, especially in the context of viral illness. As a pediatric clinician (or caregiver), the most important tasks are:
- Careful assessment — Distinguish simple fever from signs of serious illness using guidelines (e.g., NICE NG143, traffic-light systems) and clinical judgment.
- Supportive care — Use hydration, rest, and comfort measures; treat distress rather than the number alone.
- Safe use of antipyretics — Paracetamol or ibuprofen, used appropriately, can improve comfort.
- Recognizing red flags — Know when to escalate care: in young infants, persistent fever, dehydration, or neurological symptoms.
- Educate caregivers — Empower parents to safely manage fever, avoid unnecessary interventions, and seek help when needed.
By combining medical knowledge with compassionate care, we can ensure that fever in children is handled not with fear, but with informed confidence.
Relevant Website Links
- NHS – High temperature (fever) in children nhs.uk
- NICE guideline “Fever in under 5s: assessment & initial management” (NG143) Nice
- NHS Inform – Fever in children NHS Inform
- Gloucestershire Hospitals – Fever advice for children & young people gloshospitals.nhs.uk
- Royal Children’s Hospital (Australia) – Febrile child management guideline Royal Children’s Hospital
References
Elms Medical (UK). Fever in children leaflet. elmsmedicalkent.nhs.uk
NHS. High temperature (fever) in children. nhs.uk
NHS Inform. Fever in children. NHS Inform
NICE. Fever in under 5s: assessment and initial management (NG143). Nice
NCBI Bookshelf. Fever in under 5s: assessment and initial management. NCBI
NCBI Bookshelf. Feverish Illness in Children. NCBI
PubMed. Management of acute fever in children: guideline for community healthcare providers. PubMed
NHS North Tees & Hartlepool. Fever in Children. nth.nhs.uk
1. https://pothireddysurendranathreddy.blogspot.com/2025/11/acute-fever-in-adults-and-elderly-people.html fever in adult
2. https://pothireddysurendranathreddy.blogspot.com/2025/11/pain-and-bad-smell-during-urination.html foul smelling
urin
3. https://pothireddysurendranathreddy.blogspot.com/2025/11/oral-ulcers-and-dry-mouth.html oral
ulcer
Comments
Post a Comment