Heat Rash in Circular Patterns

Heat rash commonly appears as small bumps or patches where sweat and warmth collect. Several nearby areas can join visually and look curved or ring-like. A sharply enlarging ring, a scaly edge, a central clearing or a mark that continues after cooling may point to another explanation. Use the [Heat Rash](/conditions/heat-rash/) guide alongside references for [Skin Rash](/symptoms/skin-rash/) and [Skin Bumps](/symptoms/skin-bumps/).

Keep the area cool, dry and free from rubbing. Wash gently, pat dry and avoid scratching, fragranced products and thick layers that hold moisture. Take a clear photograph in good light and note whether the shape changes after sweating or cooling; this can help a clinician assess the pattern. Avoid self-treating a ring-shaped facial or body mark with steroid cream, since the wrong treatment can obscure its appearance.

Book a review if the circle enlarges, develops scale, pain, drainage or blisters, or remains when the skin is cool. Seek prompt help for fever, rapidly spreading redness, marked swelling or feeling very unwell. [Skin Redness](/symptoms/skin-redness/) can help you describe colour and change, but cannot identify the cause.

Ask whether the border, surface and timing fit heat rash or another condition, and whether testing is needed. Ask which bland moisturiser, including [Emollient Therapy](/treatments/medical-dermatology/emollient-therapy/), is appropriate and when [Topical Corticosteroids](/treatments/medical-dermatology/topical-corticosteroids/) should be avoided.