What should you know about brown scaly rash?

Atopic dermatitis often causes itch and dry, inflamed skin that can become darker after repeated rubbing. Contact dermatitis follows exposure to an irritant or allergen and may be limited to the contact area. Ringworm often expands with a more active scaly border. Psoriasis can form well-defined thick plaques, while heat rash and intertrigo favour warm, sweaty folds. Scabies usually causes intense itch, often worse at night, and may affect close contacts.

A new medicine can cause a drug rash, sometimes across much of the body. Because these patterns overlap, a clinician may ask when it began, what touched the skin, which medicines were started, and whether anyone else is itchy.

Pause newly introduced fragranced products, keep folds cool and dry, and wash gently without scrubbing. Apply a plain moisturiser to dry areas and avoid scratching. Do not use leftover steroid or antifungal medicine without advice: the wrong product can blur the appearance or worsen certain infections. If a medicine may be responsible, contact the prescriber before stopping an essential treatment.

Arrange review if the rash persists, spreads, cracks, or interferes with sleep. Get urgent help for facial swelling, breathing difficulty, skin pain, blistering, skin peeling, mouth or eye sores, fever, or a rapidly spreading rash after a new medicine. Oozing, warmth, and increasing tenderness can indicate infection.

Ask whether the distribution fits contact dermatitis, infection, or psoriasis; whether a scraping or other test is useful; and which treatment is safe for the affected body site.