Radiation Therapy and Skin Rash: Causes and Care

Yes, radiation therapy can cause a skin rash (often part of radiation dermatitis), along with redness, dryness, itching, peeling, blisters, and swelling in the treated area. ^[1] These skin reactions usually start about two weeks into treatment, may peak shortly after therapy ends, and typically improve within 3–4 weeks after finishing. ^{[1] [2]} A rash can also signal infection, so it’s important to inform your care team promptly if one appears. ^{[3] [4]}

What Skin Changes Are Common

• Pink or tanned skin that can progress to bright red or very dark. ^[5]
• Dry, tight, itchy, flaky skin; possible swelling. ^[5]
• Blisters that may open and peel. ^[5]
• Rash, especially on previously sun‑exposed areas. ^[3]
• Temporary hair loss in the treatment field. ^[3]

If reactions worsen during the week after treatment, contact your care team. ^[6]

When to Contact Your Care Team

• Skin is getting more red or swollen, feels hot or hard, or develops rash or blisters. ^[7]
• You notice drainage, new open areas, or increasing pain. ^[7]
• Any concern about infection or rapid changes. ^{[3] [7]}

Your team may adjust dressings, prescribe creams, or rarely pause treatment to allow healing if reactions are severe. ^[6]

Daily Skin Care During Radiation

• Keep skin clean with daily gentle bathing; use warm water and mild unscented soap. ^[8]
• Avoid applying thick products right before a session; residue can increase skin dose and interfere with positioning. ^[9]
• Moisturize the treated area 2–3 times daily to maintain hydration, avoiding thick layers before treatment. ^[9]
• Wear loose, soft clothing and avoid friction or rubbing. ^[10]
• Protect from extreme heat/cold (no hot tubs, heating pads, or ice packs on the field). ^[11]
• Avoid scratching; ask for soothing gel pads, saline soaks, or special dressings if itchy. ^[11]

Evidence-Based Topical Treatments

• Moisturizers: Helpful to maintain hydration; apply regularly, but avoid heavy application just before a session. ^{[12] [9]}
• Topical corticosteroids: Low to medium potency (e.g., hydrocortisone 1%, mometasone, betamethasone) can reduce inflammation and help prevent or lessen dermatitis when skin is intact. ^{[13] [14]}

There is not enough high‑quality evidence to routinely recommend natural agents such as aloe, calendula, chamomile, or curcumin for prevention. ^[15]

Dressings and Wound Care

• Aim for a moist (not wet) healing environment with non‑adherent, absorbent dressings such as hydrogels or foam depending on the level of weeping. ^[16]
• Your nurse can provide and teach the use of appropriate dressings and saline soaks if needed. ^[17]

Activity, Water, and Sun Exposure

• If you have no skin reaction, swimming in a chlorinated pool may be acceptable, but rinse off promptly; avoid oceans, lakes, and rivers if skin is broken due to infection risk. ^[18]
• Avoid tanning or burning the treated area and protect it from the sun. ^[18]

Graded Approach to Management

• Grade 1 (mild redness/itch): Continue general care; consider low to medium potency steroid if skin is intact; manage itch. ^[14]
• Grade 2 (moderate): Continue preventive care; continue topical steroids if intact; consider non‑adherent dressings and closer follow‑up. ^[14]
• Higher grades or open/weeping skin: Your team may use specialized dressings, review for infection, manage pain, and sometimes modify treatment until healing improves. ^[16]

Quick Reference: What to Do and What to Avoid

• Do: Gentle cleansing, regular moisturization (not right before therapy), loose clothing, sun protection, report changes early. ^{[8] [9] [10]}
• Avoid: Scratching, friction, adhesives over the field, perfumes or harsh products, heat/cold packs, heavy product layers before sessions, natural bodies of water if skin is open. ^{[11] [9] [18]}

What to Expect After Treatment

Skin reactions can continue or worsen for about a week after the last session, then gradually improve over several weeks; let your team know if symptoms escalate during this period. ^[6] Hair in the treated area often begins to regrow 3–6 months after therapy ends. ^[3]

Summary

• A skin rash is a known and expected side effect for many receiving radiation, often alongside redness, dryness, itch, and sometimes blisters. ^[1]
• Consistent gentle skin care, early reporting of changes, proper moisturization, and evidence‑based use of topical steroids and dressings can reduce symptoms and support healing. ^{[8] [13] [16]}
• Contact your care team for any signs of infection, worsening pain, new open areas, or rapidly progressing changes. ^[7]

If you’d like, I can help you create a personalized skin-care plan aligned with your treatment field and current symptoms.