What should you know about melanoma rash?

Melanoma can appear as a flat or raised patch with uneven borders, varied colour, or a surface that becomes scaly, crusted, or moist. It may be mistaken for eczema, irritation, a fungal rash, or an inflamed mole. Most rashes are not melanoma, and appearance alone cannot identify the cause. A lesion that stays in one place, changes gradually, or remains despite appropriate treatment deserves a clinician’s review, especially when it looks different from the surrounding skin.

Record when the patch began and photograph it in consistent lighting. Note whether it spreads, changes colour, becomes thicker, itches, hurts, crusts, or bleeds. Avoid steroid, bleaching, or antifungal treatment for a long period without a diagnosis, because partial improvement can make the pattern harder to judge. A clinician may inspect the skin with magnification and decide whether a biopsy or surgical excision is appropriate.

Arrange prompt assessment for a rash-like mark that persists, enlarges, develops several colours, bleeds without clear injury, forms a recurrent crust, or fails to heal. Seek urgent help for a rapidly spreading rash with facial swelling, breathing difficulty, fever, blistering, or severe illness. Those features can signal an acute reaction or infection and need immediate care, regardless of whether melanoma is suspected.

Ask what features make the patch more consistent with irritation, infection, eczema, or a pigmented lesion. Ask whether dermoscopy or tissue sampling is needed, how to care for the area while waiting, and which changes should prompt earlier review. Mention previous melanoma, unusual moles, immune problems, and medicines that affect the skin.