Can radiotherapy cause a skin reaction?

The skin may become pink, red, darker, dry, itchy, sore, or flaky. Some reactions become moist or blistered, especially in skin folds, and the treatment team should assess these changes.

Radiation passing through skin can temporarily affect rapidly renewing skin cells. The reaction stays mainly within the treatment field, although its shape may not be obvious without the treatment plan. The treated body site, skin folds, treatment schedule, and medicines given alongside radiotherapy can influence the reaction.

A reaction often builds gradually rather than appearing after the first session. Skin can continue changing for a while after the course ends before it begins to settle. Your radiotherapy team can distinguish an expected reaction from infection, allergy, or another skin problem.

Follow the skin-care instructions from your radiotherapy centre because products and timing may depend on the treated site. Wash gently with lukewarm water, pat rather than rub, and use only recommended moisturisers, dressings, deodorants, or medicines. Wear soft, loose clothing over sensitive areas.

Keep treated skin away from direct sun and avoid heat packs, ice packs, adhesive tape, scratching, shaving irritation, and swimming if the skin is broken. Do not remove treatment marks unless the team says this is acceptable. Report discomfort early so suitable pain relief or dressings can be arranged.

Contact the radiotherapy team promptly if skin becomes blistered, weeps, bleeds, opens, or is too painful for normal activities. Spreading redness, increasing warmth or swelling, pus, unpleasant odour, fever, or feeling unwell can indicate infection and needs timely assessment.

Seek urgent help for facial or throat swelling, difficulty breathing, or a rapidly spreading rash beyond the treated region, as these may represent a serious reaction unrelated to routine radiation dermatitis.

Ask which part of your skin lies in the treatment field, which cleanser and moisturiser to use, when to apply products around sessions, and whom to call after hours. Clarify whether existing eczema, psoriasis, scars, or current medicines alter your care plan.