Heat rash between the leg and groin: what to know

The area may feel prickly, itchy, sore or stinging. Small raised spots, patches of skin rash or changes in redness can occur where the surfaces touch. On deeper skin tones, inflammation may look brown, purple, grey or darker than the surrounding skin rather than bright red. A rash in this location can have other causes, including contact irritation or a fungal infection, so appearance alone cannot confirm heat rash.

Heat rash is encouraged by tight clothing, exercise, humid weather and sitting or walking for long periods. Scratching can break the skin and make irritation or infection more likely. See the related explanation of [Heat Rash](/conditions/heat-rash/) and symptom pages for [Skin Rash](/symptoms/skin-rash/) or [Skin Redness](/symptoms/skin-redness/).

Gently wash with lukewarm water, pat dry and give the fold time to cool. Choose loose, breathable underwear and change out of damp clothing promptly. Reduce rubbing during activity, and avoid fragranced products, harsh scrubbing and thick occlusive ointments unless a clinician recommends them. Do not share towels.

A bland moisturiser may help when the skin is dry or chafed; information about [Emollient Therapy](/treatments/medical-dermatology/emollient-therapy/) can help you understand this option. A clinician may recommend a medicine for inflammation, but do not apply a steroid cream to a suspected infection without advice; read about [Topical Corticosteroids](/treatments/medical-dermatology/topical-corticosteroids/) before using one.

Arrange a medical assessment if the rash is spreading, repeatedly returning, very painful, cracked, wet, foul-smelling or producing pus. Seek prompt care for fever, rapidly increasing swelling, warmth or tenderness, or red streaking. If cooling and gentle skin care do not start improving the area, a clinician can check for infection, eczema or another condition and choose treatment safely.

Ask what diagnosis best fits the pattern, whether a swab or other check is needed, which products are safe in the groin fold, and how to prevent recurrence during exercise or hot weather.