Management of Prickly Heat Rash (Miliaria)
Prickly heat rash is a self-limiting condition that resolves spontaneously within hours to days once heat exposure is removed and the skin is kept cool and dry, requiring primarily supportive care rather than active medical intervention. 1
Immediate Management: Environmental Control
The cornerstone of treatment is removing the patient from the hot, humid environment and allowing the skin to cool and dry. 1, 2
- Move to a cool, air-conditioned environment immediately to stop further sweat duct obstruction 3
- Remove wet or occlusive clothing and replace with loose, breathable cotton garments 2
- Heat intolerance from miliaria rubra can persist for up to 21 days even after environmental modification 4
Skin Care Measures
Keep affected skin clean and completely dry through gentle cleansing and avoiding further heat exposure. 2
- Use lukewarm (not hot) water for bathing to avoid stimulating additional sweat production 5
- Apply gentle, pH-neutral cleansers rather than harsh soaps that strip natural skin lipids 6
- Avoid applying moisturizers, creams, or occlusive products to affected areas, as greasy preparations can worsen the condition by trapping heat and promoting secondary infection 7
- Pat skin dry thoroughly after washing rather than rubbing 8
Symptomatic Relief for Pruritus
For itching, low-potency topical corticosteroids can be applied 3-4 times daily for short-term relief. 8
- Hydrocortisone 1-2.5% cream or ointment applied to affected areas not more than 3-4 times daily provides anti-inflammatory relief 8
- Oral antihistamines with sedative properties (such as diphenhydramine) may provide short-term relief during severe pruritus, though their benefit is primarily through sedation rather than direct antipruritic effect 6
- Non-sedating antihistamines have minimal value for heat rash 6
Monitoring for Complications
Watch closely for signs of secondary bacterial infection, particularly Staphylococcus superinfection, which can complicate miliaria rubra. 2
- Signs of infection include: crusting, weeping, yellow discharge, painful lesions, or pustules spreading beyond the original rash distribution 6
- If infection is suspected: obtain bacterial culture and initiate appropriate antibiotics based on sensitivities 6
- Patients with extensive body surface area involvement (>17%) may experience significant heat intolerance requiring up to 3 weeks for full recovery 4
Prevention Strategies
Preventing recurrence requires ongoing attention to environmental factors and clothing choices. 3, 2
- Maintain cooler working/living environments with adequate air circulation; underground temperatures above 27°C wet bulb significantly increase miliaria incidence 3
- Wear loose, breathable cotton clothing and avoid synthetic or flame-resistant blend fabrics in hot environments 2
- Change clothing regularly when perspiration-soaked to keep skin dry 2
- Ensure thorough laundering to remove detergent residue from fabrics, which can contribute to skin irritation 2
- Avoid excessive sun exposure and hot blow-drying, which aggravate the condition 5
Common Pitfalls to Avoid
Do not apply heavy emollients, moisturizers, or occlusive dressings to active miliaria, as these trap heat and worsen sweat duct obstruction. 7
- Avoid hot water bathing or showering, which stimulates additional sweating 5
- Do not use topical acne medications on heat rash, as these cause irritation and excessive drying 5
- Do not overtreat with antiseptic creams, which can irritate the skin further 6
- Avoid alcohol-containing preparations that increase skin dryness 7
When to Escalate Care
Refer to dermatology if the rash does not resolve within 1-2 weeks of environmental modification, or if signs of secondary infection develop despite appropriate treatment. 5