Multiple myeloma and skin cancer: what to know

Myeloma develops from abnormal plasma cells in bone marrow. A new mole, scaly patch, sore, rash, bruise, or lump on the skin is not enough to identify its cause. Medicines may cause rashes, dryness, sensitivity, or changes in bruising, while infection can also affect the skin when immunity is reduced. A clinician may examine the area, review medicines, and arrange a skin specialist review or biopsy when needed.

Photograph a changing area in good light and note when it began, whether it bleeds or hurts, and any recent medicine changes. Do not stop myeloma treatment without speaking with the prescribing team. Show persistent, spreading, bleeding, crusting, or non-healing changes to a doctor. The assessment may involve your haematologist, primary-care clinician, or dermatologist depending on the finding.

Get urgent help for a rapidly spreading rash, facial swelling, blistering, peeling skin, sores in the mouth, fever with a skin change, or trouble breathing. These features can signal a serious medicine reaction or infection, particularly during treatment that affects immune function.

Ask whether the change could relate to a medicine, infection, or an independent skin condition; whether any treatment should be paused; and whether examination, photography, or biopsy is needed. Ask which symptoms should trigger an urgent call.