Heat Rash on Forearms Only

Forearms can react where sunlight, exercise sweat, tight sleeves, protective gear, or a new lotion keeps heat against the skin. Heat rash may cause tiny bumps, itching, prickling, or redness. A rash confined to exposed forearms can also reflect contact with sunscreen, plants, detergents, or fabric, so the distribution provides a clue rather than a diagnosis. Compare both arms and note whether the change follows a sleeve edge or product application.

Cool the forearms with a clean damp cloth, then wash gently and pat dry. Wear loose, breathable sleeves and take breaks from equipment that rubs or seals in perspiration. Stop newly introduced fragranced products until the skin is calm, and avoid scratching or vigorous exfoliation. A light emollient may help if the surface feels dry, while a topical corticosteroid should be used only with suitable advice, especially if the diagnosis is uncertain. Keep the area protected from further overheating.

Speak with a clinician if the rash remains after cooling and avoiding suspected triggers, spreads beyond the forearms, or returns repeatedly. Seek prompt assessment for marked swelling, pain, warmth, pus, crusting, fever, blisters, or rapidly worsening redness. Get urgent help for facial or throat swelling, breathing difficulty, faintness, or widespread hives.

Does the sleeve pattern suggest heat, friction, or contact irritation? Could a medicine or skincare product be contributing? Which moisturiser is appropriate? Should I use any medicated cream, and what symptoms should prompt a follow-up?