What should you know about TKI rash?

A rash may appear as redness, small bumps, dryness, scaling, itching, tenderness, or acne-like spots. Its location and timing can help the oncology team distinguish a medicine-related eruption from contact dermatitis, heat rash, fungal infection, scabies, or another condition. Some reactions are mild; others can involve pain, skin peeling, blisters, or sores.

Do not assume every new mark is caused by the TKI, and do not stop, restart, or reduce the medicine without the prescribing team. Photographing the rash and recording when it began, where it spread, and which products touch the skin can make the review more useful.

Tell your oncology team promptly about a new or changing rash. Use gentle, fragrance-free cleanser and moisturiser unless your team advises otherwise. Avoid hot showers, harsh exfoliants, fragranced products, and scratching. Wear loose clothing and protect exposed skin from strong sunlight. The clinician may recommend a prescribed cream, anti-itch medicine, or another treatment while deciding whether the cancer medicine needs adjustment.

Keep a list of all medicines, supplements, and skin products. A rash can also resemble [Drug Rash](/conditions/drug-eruption/) or [Atopic Dermatitis](/conditions/atopic-dermatitis/), so examination matters.

Seek urgent medical help for blistering, skin peeling, painful sores, rash around the eyes or mouth, fever, facial swelling, breathing difficulty, or a rapidly spreading eruption. Contact the oncology team quickly if the rash is painful, infected-looking, interfering with sleep, or preventing eating, drinking, or normal activities.

Ask whether the appearance and timing fit a TKI reaction, which products are safe, how to grade changes in severity, when to send photographs, and which symptoms require emergency care. Ask before taking an over-the-counter steroid, antihistamine, or antibiotic.