How heat rash can appear on brown skin

Heat rash happens when sweat is held near the surface and the skin becomes irritated. On brown skin, redness may be subtle or appear as a deeper brown, purple or dusky change rather than bright red. Tiny bumps, clear blisters, prickling, warmth and itch can be easier to notice than colour alone. Compare both sides and observe whether the area follows sweating, tight clothing or a skin fold. Skin Redness and Skin Bumps provide useful symptom language.

Cool the area with a clean damp cloth, then pat it dry. Wear loose, breathable fabric and keep folds dry; avoid vigorous rubbing, scrubs, fragranced sprays and heavy layers that seal in sweat. Do not scratch or pop blisters, since broken skin can change colour while healing and can invite infection. If the skin is dry after the heat settles, a fragrance-free emollient may reduce friction; see Emollient Therapy. A clinician can decide whether Topical Corticosteroids are appropriate for marked inflammation.

Seek medical advice if the rash persists, spreads, becomes painful, forms repeated blisters or leaves a marked change in colour. Prompt assessment is needed for increasing warmth, swelling, drainage, fever, skin breakdown or rapidly changing purple or dark areas. These signs can reflect infection or another skin problem, and colour alone should not be used to judge severity.

What features make this heat rash rather than eczema, infection or contact irritation? Which colour or texture changes should I photograph? How can I protect the area while it heals? Is treatment needed if the itch continues?