Fever in children is one of the most common reasons for emergency visits — most cases are caused by self-limiting viral infections, but specific patterns and accompanying symptoms determine urgency.
A child's immune system mounts higher and faster fever responses than adults. A temperature ≥38°C (100.4°F) is significant in infants under 3 months; ≥39°C (102.2°F) warrants careful assessment in older children. The child's appearance — whether they look 'toxic', are responding normally, or are consolable — is more important than the exact temperature reading.
Viral upper respiratory infection
Most common cause in children. Associated with runny nose, sore throat, mild cough. Self-limiting in 5–7 days.
Common in toddlers. Ear pain, irritability, and pulling at ears alongside fever.
Urinary tract infection
Often missed in young children — may present with fever alone, especially in girls under 5. Urine dipstick/culture required.
Roseola (HHV-6)
High fever 39–40°C for 3–4 days, then sudden defervescence with rash — classic presentation ages 6 months–2 years.
Must be excluded in any child with fever after travel to tropical regions. Can be rapidly fatal in children.
May present with fever and lymphadenopathy in older children — serology required if suspected.
A fever in children is defined as a temperature ≥38°C (100.4°F) by any measurement method. Temperatures ≥38.5°C (101.3°F) are definitively febrile. In infants under 3 months, any temperature ≥38°C requires immediate medical evaluation regardless of how well they appear.
Both paracetamol and ibuprofen are safe and effective for reducing fever in children over 3 months. Ibuprofen is not recommended under 3 months. Alternating both every 3–4 hours can help with high or persistent fever. Do not give aspirin to children under 16 (Reye syndrome risk).
Most childhood fevers (80–90%) are viral and self-limiting. Signs suggesting viral rather than bacterial cause include: gradual onset, associated runny nose/cough/sore throat, absence of localised pain, child who appears well between fever peaks, and fever resolving within 3–5 days.
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