How to treat heat rash in infants and young children?

Treatment of Heat Rash in Infants and Young Children

Heat rash (miliaria rubra) in infants and young children is best managed by cooling measures—moving the child to a cooler environment, removing excess clothing, and allowing the skin to cool naturally, which typically leads to resolution without medication. 1

Immediate Management

Cool the affected child immediately by implementing these specific measures:

• Move the infant or child to a cooler, air-conditioned environment or shaded area 1
• Remove excess clothing and any occlusive garments that trap heat and moisture 1
• Allow the skin to air dry naturally without applying additional products initially 1
• Ensure adequate hydration with 100-250 mL (approximately 3-8 oz) of fluid every 20 minutes for children aged 9-12 years, adjusted downward for younger infants 2

When Topical Treatment May Be Considered

For persistent or symptomatic cases with significant pruritus, topical hydrocortisone 1% may be applied:

• Apply to affected areas not more than 3 to 4 times daily for children 2 years of age and older 3
• Do NOT use hydrocortisone for diaper rash or in children under 2 years without consulting a physician 3
• Discontinue use if the condition worsens or persists beyond 7 days 3

Critical Distinction: Heat Rash vs. Exertional Heat Illness

Heat rash itself is benign, but you must distinguish it from more serious heat-related conditions:

• Simple miliaria rubra presents as small red papules or vesicles in areas of heat and moisture exposure without systemic symptoms 1
• If the child exhibits altered mental status, weakness, dizziness, nausea, or syncope, this indicates heat exhaustion or heat stroke—not simple heat rash—and requires immediate emergency management 2, 4
• Any child with CNS dysfunction or core temperature ≥40°C (104°F) requires immediate activation of EMS and rapid whole-body cooling 4

Prevention Strategies

Prevent recurrence by addressing the underlying heat and moisture exposure:

• Dress infants and young children in lightweight, breathable, loose-fitting clothing 2
• Avoid overdressing children, particularly during sleep 1
• Maintain cool ambient temperatures when possible 1
• Recognize that heat rash results from immaturity of skin structures in infants, making them particularly susceptible 1

Common Pitfalls to Avoid

• Never apply occlusive ointments or thick creams to heat rash, as these worsen the condition by further blocking sweat ducts 1
• Do not confuse heat rash with other vesiculopustular rashes such as erythema toxicum neonatorum, candida, or bacterial infections—these require different management 1
• Avoid using topical steroids in the diaper area or on children under 2 years without physician guidance 3
• Do not delay evaluation if systemic symptoms develop, as this may indicate progression to heat exhaustion requiring different management 2, 4

Expected Course

Most cases of miliaria rubra resolve within days once cooling measures are implemented, though parental reassurance and observation are usually sufficient 1. Heat intolerance from extensive heat rash may persist for up to 21 days in severe cases 5, but simple cooling measures remain the primary intervention.