What should you know about skin cancer rash?

Skin cancer can appear as a patch, plaque, sore or scaly area rather than a classic rash. Possible clues include one area that remains different from nearby skin, repeatedly crusts or bleeds, enlarges, changes colour, or does not settle after removing an obvious irritant. These features do not diagnose cancer. Atopic dermatitis, contact dermatitis, drug rash, heat rash, intertrigo, psoriasis, ringworm and scabies can all produce rashes with different patterns and triggers. A clinician considers the distribution, texture, symptoms, medicines, exposures and duration. A dermatoscope or a small biopsy may be used when the appearance is unclear.

Photograph the rash in good light and note when it began, whether it spreads, and any new product, medicine, travel or contact exposure. Use gentle, fragrance-free cleansing and avoid scratching or applying steroid, antifungal or antibiotic creams unless advised for this rash. Arrange a skin examination if the area persists, returns in the same place, or changes despite simple care. Bring a list of medicines and products to the appointment.

Seek urgent medical help for a rash with facial or throat swelling, breathing difficulty, blistering, skin peeling, confusion or severe weakness. Arrange prompt review for rapidly spreading redness, severe pain, pus, fever or a sore that bleeds repeatedly. A slow, isolated change still warrants a routine examination when it does not heal or keeps evolving.

Ask what pattern the rash has, which causes are being considered, whether a biopsy is needed, what treatments are safe before diagnosis, and what change should trigger an earlier review. Ask how to protect the area from sun and how follow-up will be arranged if it remains abnormal.