What should you know about red rash?

Look at how quickly it appeared, whether it itches or hurts, and whether the skin is raised, scaly, blistered, ring-shaped, or moist. New soap, cosmetics, clothing, plants, sweat, friction, and medicines can irritate skin. Atopic dermatitis often causes itchy, dry, inflamed patches; contact dermatitis can follow exposure to a particular substance. Heat rash tends to affect areas that become hot or sweaty. Scabies can be intensely itchy, while ringworm may form a spreading scaly ring. A rash may also occur with psoriasis or in skin folds as intertrigo. These patterns guide an examination, but appearance alone cannot confirm a diagnosis.

Gently wash with lukewarm water, stop any newly introduced skin product, and use a plain fragrance-free moisturiser if the skin is dry. Keep sweaty areas cool and dry, avoid scratching, and choose loose clothing. Do not share towels, razors, or bedding if an infection is possible. Photograph the rash and note recent medicines, products, travel, illness, and exposures; this can help a clinician identify a trigger. Avoid applying a strong steroid or multiple combination creams without advice, especially on the face.

Seek urgent medical help for trouble breathing, swelling of the lips or tongue, faintness, a rapidly spreading rash, widespread blistering, skin peeling, severe pain, or sores involving the eyes or mouth. Prompt assessment is also sensible when fever, feeling very unwell, pus, warmth, or red streaks accompany the rash, or when it began after a new medicine. Arrange a routine review if it persists, repeatedly returns, or does not improve after removing a likely irritant.

Could this pattern fit contact dermatitis, eczema, infection, or a medicine reaction? Which products should I pause, and what is safe for this body area? Do I need testing, treatment, or a review if the rash changes?