Heat rash under the breast: what to know

Sweat can become trapped around the breast fold, while close skin contact and clothing reduce airflow. The result may be small bumps, stinging, itching or a red patch. Heat rash is also called miliaria or prickly heat; see the Heat Rash guide for an overview. A rash in this location can have other causes, including irritation from detergent, a yeast-related fold infection or eczema, so appearance alone cannot confirm the cause.

Skin Bumps, Skin Rash and Skin Redness describe the main visible changes. Note whether the area is dry or weeping, whether symptoms began after exercise or hot weather, and whether the rash affects one side or both.

Gently rinse the fold with lukewarm water and a mild, fragrance-free cleanser, then pat it completely dry. Use a cool environment, loose breathable clothing and a clean, dry cotton layer to reduce rubbing. Change damp bras or clothing promptly, and avoid scratching, heavy oils, fragranced powders and products that seal in moisture.

If the skin is intact and dry, a suitable emollient may protect against friction; read about Emollient Therapy. Do not apply a steroid cream to a moist or infected-looking fold unless a clinician has advised it; Topical Corticosteroids need the right strength and diagnosis.

Arrange a medical assessment if the rash is spreading, painful, hot, cracked, draining fluid, developing a bad smell or not settling after removing heat and moisture. Seek prompt care for fever, rapidly worsening redness, marked swelling or feeling unwell. A clinician can distinguish heat rash from infection or another inflammatory rash and choose treatment that is safe for a skin fold.

Could this be heat rash, contact irritation, eczema or a fold infection? Which cleanser or barrier product is appropriate? Should I stop any deodorant, detergent or cream? What changes would mean I need a review?