What is the management and treatment for heat rash (miliaria)?

Management and Treatment of Heat Rash (Miliaria)

The primary management of heat rash (miliaria) involves keeping the affected area cool, clean, and dry to promote healing and prevent complications. 1 This condition results from blocked sweat ducts and sweat retention, with heat and humidity being the main causative factors.

Types of Heat Rash

Heat rash presents in different forms:

• Miliaria crystallina: Clear, fluid-filled vesicles on the skin surface
• Miliaria rubra: Red, pruritic papules (most common form)
• Miliaria profunda: Deeper, flesh-colored papules

Treatment Algorithm

First-Line Management

1. Remove from hot environment

   • Move to a cool, well-ventilated area
   • Reduce ambient temperature when possible

2. Cooling measures

   • Use air conditioning or fans to promote evaporation
   • Take cool showers or baths
   • Apply cool compresses to affected areas

3. Keep skin clean and dry

   • Wash affected areas with a gentle, pH-neutral cleanser 2
   • Pat dry thoroughly (don't rub)
   • Avoid excessive sweating

4. Reduce friction

   • Wear loose-fitting, lightweight, cotton clothing
   • Avoid tight garments that trap heat and moisture
   • Change wet clothing promptly

Second-Line Management (for symptomatic relief)

1. Topical treatments

   • For pruritus: Low to medium-potency topical corticosteroids (apply thin film 2-3 times daily for 5-7 days) 3
   • For cooling sensation: Calamine lotion or menthol-containing preparations
   • For drying: Drying pastes for moist areas, particularly in skin folds 2
   • Avoid: Greasy topical products that inhibit absorption of sweat and promote superinfection 2

2. Oral medications (for severe pruritus)

   • Antihistamines may provide symptomatic relief of itching
   • For extensive rash (>10% body surface area), consider alternative antihistamines 3

Management of Complications

1. Secondary bacterial infection

   • Should be treated if present 2
   • Consider topical antibiotics if signs of infection develop
   • Systemic antibiotics rarely needed unless infection is extensive

2. Persistent or severe cases

   • Consider dermatology referral if:
     • Rash persists >2 weeks despite treatment
     • Signs of secondary infection worsen
     • Rash covers >30% of body surface area 3

Prevention Strategies

1. Environmental modifications

   • Maintain cool, well-ventilated environment
   • Use air conditioning or fans during hot weather
   • Avoid excessive heat exposure

2. Personal measures

   • Wear loose, lightweight clothing
   • Change wet clothing promptly
   • Take cool showers after sweating
   • Use absorbent powders in skin folds (avoid cornstarch-based products)

3. Gradual heat acclimatization

   • Particularly important for those returning to hot environments
   • Heat intolerance due to miliaria rubra may persist up to 21 days 4

Special Considerations

• Athletes/Military Personnel: May require more aggressive prevention strategies due to unavoidable heat exposure 5
• Infants: More susceptible due to immature sweat ducts; keep cool and dress appropriately
• Elderly: May have impaired thermoregulation; monitor closely in hot environments

Prognosis

Heat rash is generally self-limited and resolves within 7-10 days with proper management. However, extensive miliaria rubra can impair sweating and lead to heat intolerance for up to 3 weeks, potentially increasing risk for more serious heat-related illnesses 4.

The key to successful management is early intervention with cooling, drying, and reducing friction on affected skin areas, while preventing secondary infection and addressing any symptomatic discomfort.