Small bumpy rash: what to know

An itchy, dry rash may occur with atopic dermatitis or contact dermatitis. Heat rash favours sweaty or covered areas. Intertrigo affects skin folds where moisture and friction meet. Ringworm may form a scaly edge, while scabies often causes intense itch and can affect household contacts. Psoriasis may produce well-defined scaly areas. A rash that begins after a medicine can be a drug eruption, even when the medicine was previously tolerated.

These patterns are clues rather than a diagnosis. Note the first site, speed of spread, itch or pain, scaling, blisters, fever, and every medicine or product started recently. Do not stop a prescribed medicine without advice unless emergency services tell you to do so.

Use lukewarm water, a gentle cleanser, and a plain moisturiser. Keep folds cool and dry, wear loose breathable clothing, and avoid scratching, fragranced products, and new cosmetics until the cause is clearer. Do not share towels, bedding, or clothing if an infectious rash is possible, and wash hands after touching affected skin.

Arrange a clinical assessment if the rash persists, spreads, returns, or follows a new medicine. Treatment differs widely: eczema care, antifungal treatment, scabies treatment, and medicine review are not interchangeable.

Seek urgent medical care for a rash with breathing difficulty, facial or tongue swelling, faintness, blistering, skin peeling, purple spots that do not fade with pressure, severe pain, or high fever. Prompt assessment is also needed when the eyes, mouth, or genitals are involved, or when an infant appears very unwell.

Could this be contact dermatitis, heat rash, ringworm, scabies, psoriasis, or a medicine-related eruption? Is it contagious? Which products should I stop, and what signs mean I need urgent review?