Side Effects of Melanoma: Symptoms and When to Seek Care

Melanoma may cause changes in a mole or skin area, while advanced disease and its treatments can produce different symptoms and side effects that need medical review. The cancer itself may be quiet at first, so a changing spot deserves assessment even when it does not hurt. Side effects can also come from surgery, immunotherapy, or other cancer treatment rather than from melanoma directly.

A melanoma can show a mole or patch becoming asymmetrical, developing an uneven border, changing colour, enlarging, or evolving in another noticeable way. It may itch, bleed, crust, become tender, or form an area that does not heal, although none of these changes proves that a spot is melanoma. If melanoma spreads, symptoms depend on the organ involved. Persistent tiredness, unexplained weight loss, swollen lymph nodes, persistent pain, cough, headaches, weakness, or changes in vision can have many causes but should be reported when melanoma is known or suspected. Brain metastases can cause neurological symptoms and require prompt assessment.

Treatment effects follow a different pattern. Excision can leave soreness, bruising, swelling, numbness, tightness, or a scar near the wound. Immunotherapy can activate the immune system against healthy organs, leading to diarrhoea, rash, itching, joint pain, fatigue, cough, shortness of breath, or changes in thyroid and other hormone function. Tell the oncology team about new symptoms early; do not wait for them to become severe.

Arrange a dermatology review for a changing, bleeding, or non-healing spot. Do not pick at it or remove it yourself. Photographing the area beside a ruler can help show change over time, but a photograph cannot replace examination. A clinician may inspect the whole skin surface, feel nearby lymph nodes, and recommend a biopsy or other staging assessment.

If you are receiving treatment, keep a simple record of when symptoms began, how often they occur, medicines you take, bowel changes, temperature, and any breathing or neurological symptoms. Contact the treating team using its out-of-hours instructions before taking a new medicine for a suspected treatment reaction.

Seek emergency care for severe trouble breathing, chest pain, fainting, sudden confusion, a seizure, new weakness on one side, difficulty speaking, or a sudden severe headache. During immunotherapy, urgent advice is also needed for rapidly worsening diarrhoea, blood in the stool, severe abdominal pain, yellowing of the skin or eyes, very little urine, or a widespread blistering rash.

Contact your melanoma or oncology team promptly for a fever, a new or worsening symptom, marked fatigue, persistent vomiting, new cough, vision changes, or a wound that becomes increasingly red, hot, swollen, painful, or draining. The urgency depends on the symptom and treatment, not on how likely a symptom is to represent melanoma.

Ask which symptoms could come from melanoma, which could be treatment effects, and whom to contact outside clinic hours. You can also ask what changes in a surgical wound are expected, whether you need skin and lymph-node checks, how symptoms will be investigated, and which medicines or supplements should be avoided during treatment.