Underarm sweat rash treatment

Heat rash, also called prickly heat or miliaria, develops when sweat becomes trapped or the skin stays warm and damp. Underarm folds are exposed to friction from clothing and skin contact, so redness, small bumps, stinging or itch can appear. A rash that is spreading, very tender, crusted or associated with drainage may have a different cause, such as irritation, allergy or infection. See the related guides to [Heat Rash](/conditions/heat-rash/), [Skin Rash](/symptoms/skin-rash/), [Skin Bumps](/symptoms/skin-bumps/) and [Skin Redness](/symptoms/skin-redness/).

Wash gently with lukewarm water, pat dry and choose loose, breathable clothing. Pause fragranced deodorants, shaving and products that sting until the surface settles. A cool compress can reduce discomfort. A plain moisturising barrier may help when rubbing or dryness is contributing; ask a pharmacist or clinician whether [Emollient Therapy](/treatments/medical-dermatology/emollient-therapy/) fits your skin. Do not scratch or apply steroid cream to broken, infected-looking skin without advice. A clinician may recommend [Topical Corticosteroids](/treatments/medical-dermatology/topical-corticosteroids/) for selected inflammatory rashes.

Arrange medical advice if the rash is painful, rapidly worsening, recurrent, spreading beyond the fold or not settling after removing heat and friction. Prompt assessment is appropriate for pus, yellow crusting, marked swelling, fever, or red streaks. Seek urgent help for facial swelling, breathing difficulty or a rapidly widespread reaction.

Ask whether this looks like heat rash or contact dermatitis, whether a product should be stopped, and which moisturiser or medicine is suitable for the exact area. Mention new deodorants, laundry products, exercise, shaving, diabetes, medicines and how quickly the rash appeared.