Itchy red bumps that are spreading: what to know

A rash that expands after a new detergent, cosmetic, plant, adhesive, or medicine may reflect contact dermatitis. Dry, scaly, inflamed patches can occur with eczema, while raised areas that appear and fade may be hives. A ring-like edge, crusting, pain, warmth, or drainage may suggest an infection or another process.

Itching at night, affected household members, or bumps between the fingers and around the waist are details worth reporting because scabies can spread through close contact. The direction of spread does not identify one diagnosis by itself.

Take clear photographs in good light and mark when the change began. Stop newly introduced skin products, wash clothing and bedding with your usual detergent, and avoid scratching or sharing towels. Keep nails short and use a plain moisturiser on dry, unbroken skin.

Avoid applying several creams together or using someone else’s prescription. A clinician may need to see the active rash, ask about exposures and contacts, and decide whether testing or targeted treatment is needed.

Get medical advice promptly when the rash is rapidly expanding, painful, hot, draining, blistering, or accompanied by fever or feeling unwell. Seek emergency help for breathing difficulty, facial or tongue swelling, faintness, skin peeling, or a rash involving the eyes.

Ask whether the pattern fits contact dermatitis, atopic dermatitis, hives, scabies, a yeast infection, psoriasis, or another condition; whether close contacts need advice; and which treatment is safe for the affected sites.