What should you know about body heat rash?

Heat rash, also called miliaria or prickly heat, can occur when sweat ducts become blocked and sweat remains under the skin. It often appears in skin folds, under clothing, on the neck, chest, back or groin, especially after hot, humid conditions or heavy sweating. The area may feel prickly, itchy or tender. The appearance can range from tiny clear or red bumps to a more inflamed skin rash.

Heat rash is different from hives: hives are usually transient raised welts, while heat rash tends to remain in the area where sweat and friction have irritated the skin. Scratching, thick creams and tight clothing may worsen blockage or rubbing.

Cool the body, take a gentle lukewarm rinse and pat the skin dry. Wear loose, breathable clothing and change out of damp garments promptly. Keep affected folds clean and dry, and avoid fragranced products, heavy ointments and vigorous scrubbing while the skin is inflamed. A light emollient therapy product may help if dryness develops, but ask a pharmacist which formulation suits a heat-prone area. Do not use topical corticosteroids on large or delicate areas without professional advice.

Get medical advice if the rash spreads, becomes painful, produces pus, forms blisters, or does not improve after cooling and reducing sweat. Fever, marked weakness, confusion or dizziness after heat exposure needs urgent assessment because it may indicate a heat illness rather than a simple rash. Seek emergency help for breathing difficulty, facial swelling or fainting.

Does this pattern fit heat rash or another skin condition? Which cleanser and moisturizer are suitable for the affected area? Would a short course of topical corticosteroids be appropriate? How can I prevent recurrence during exercise, travel or hot weather?