Skin rash without fever or itching

A flat change in colour may follow irritation, sun exposure or inflammation. Rough or scaly patches can occur with psoriasis or dermatitis, while ring-shaped scaling can suggest ringworm. Heat rash, intertrigo and some medication eruptions may also be mild at first. Lack of fever or itch does not identify the cause and does not rule out a condition that needs treatment.

Photograph the area and note when it started, whether it is enlarging, and any new medicines, foods, products, clothing or outdoor exposures. Clean gently, keep the skin dry, and avoid experimenting with multiple creams. Do not stop a prescribed medicine without medical advice, but contact the prescriber promptly if the rash began after a new drug.

Get urgent help for breathing difficulty, facial or tongue swelling, faintness, purple or bruise-like spots, skin pain, blistering, peeling, or sores in the mouth or eyes. Arrange a clinical review if the rash spreads quickly, becomes warm or tender, develops drainage, or does not settle after removing a suspected irritant.

What features make this look like dermatitis, infection, psoriasis or a medication eruption? Could any recent product or medicine be responsible? Do I need an examination or skin test? Which changes require same-day care?