Heat rash in the scalp: what to know

Sweat-duct blockage can produce tiny red bumps or an irritated, prickly patch on a hot scalp. Helmets, caps, wigs, thick hair products and vigorous activity may keep heat and moisture close to the skin. Tender bumps around individual hairs can have other causes, such as follicle inflammation. Compare the pattern with [Skin Bumps](/symptoms/skin-bumps/) or [Skin Rash](/symptoms/skin-rash/), but remember that a clinician may need to inspect the scalp to tell conditions apart.

Move to a cooler setting, remove headwear when safe and wash away sweat with a gentle shampoo. Rinse thoroughly and let the scalp dry before replacing a cap or helmet. Avoid oily styling products, fragranced sprays and picking at bumps. Use a clean cool cloth for short periods if it feels soothing. If the scalp is dry after washing, ask about [Emollient Therapy](/treatments/medical-dermatology/emollient-therapy/); do not put a [Topical Corticosteroids](/treatments/medical-dermatology/topical-corticosteroids/) product on the scalp unless a professional has advised it.

Seek medical advice if scalp bumps persist after reducing heat, spread, recur often or cause hair loss. Arrange prompt care for severe tenderness, pus, crusting, marked swelling, fever, a rapidly spreading rash or eye-area involvement. A painful scalp eruption may need a different treatment from simple heat rash, so avoid squeezing or sharing combs, hats or towels.

Ask whether the bumps arise from sweat ducts, follicles or another condition, which shampoo is suitable, and whether headwear or hair products should be changed. Mention recent exercise, heat exposure, new products and any drainage.