Heat rash on the inner arm: causes and care

The inner arm can stay warm beneath sleeves or against the body. Trapped sweat may cause prickling, itch and tiny bumps, with mild [Skin Redness](/symptoms/skin-redness/). The appearance may fit [Heat Rash](/conditions/heat-rash/), but [Skin Bumps](/symptoms/skin-bumps/) and [Skin Rash](/symptoms/skin-rash/) can also result from allergy, irritation or infection.

Cool the area with a clean, damp cloth, then pat dry. Choose loose sleeves made from breathable fabric and change clothing after sweating. Pause new deodorants, fragranced products and rubbing straps until the skin recovers. Avoid scratching and thick layers that trap heat. If the surface is dry rather than wet or inflamed, a suitable bland moisturiser may help; [Emollient Therapy](/treatments/medical-dermatology/emollient-therapy/) explains this approach. Use [Topical Corticosteroids](/treatments/medical-dermatology/topical-corticosteroids/) only when a clinician recommends one.

Arrange assessment when symptoms persist, recur, or interfere with sleep or movement. Seek prompt care for spreading redness, severe pain, warmth, swelling, pus, blisters, fever or a red streak moving up the arm. These features can point to infection or another condition needing different treatment.

Ask whether sweat, friction, contact irritation or infection best explains the pattern, which cleanser and moisturiser suit your skin, and how long to try the plan. Mention new products, exercise, work clothing and any drainage.