What should you know about a rash?

Describe when it began, where it started, whether it itches or hurts, and whether it is dry, scaly, ring-shaped, blistered or moist. A rash can be a presentation of Atopic Dermatitis, Contact Dermatitis, Drug Rash, Heat Rash, Intertrigo, Psoriasis, Ringworm or Scabies. These conditions can look alike, so appearance alone cannot confirm the cause. New medicines, products, heat, sweating, travel and close contact are useful details for a clinician.

Use lukewarm water, a gentle cleanser and an unperfumed moisturiser. Avoid scratching, fragranced products and any recently introduced cream that seems to worsen the area. Keep the skin cool and dry, and do not share towels if infection is possible. Take a clear photo and note exposures or medicines before an appointment. Avoid applying steroid or antifungal medicine without advice when the diagnosis is uncertain.

Get urgent help for breathing difficulty, facial swelling, faintness, a rapidly spreading rash, extensive blistering, skin peeling, severe pain, purple spots or involvement of the eyes or mouth. Arrange prompt review for fever, pus, warmth, rapidly increasing redness, or a rash after starting a medicine. A persistent or recurring rash also deserves assessment.

What pattern does this rash suggest? Could a medicine, product, heat or contact exposure be involved? Do I need testing, prescription treatment or precautions for people at home?