Radiation therapy can cause side effects to your skin. The side effects you have depend on the type of cancer. They also depend on where the tumor is and the radiation therapy dose. They also depend on your general health, your medical conditions, and also medications you are taking. Keep in mind that side effects don't affect how well the radiation therapy works on your cancer.

Some skin side effects take several days or weeks to develop. Some skin reactions may occur days, weeks, or longer after your treatment ends.

Keep your radiation therapy ink marks from fading. These marks are used to help position your body for radiation therapy. Don't scrub them when you bathe. Let water run over them. Pat them dry gently. Don't remove marks until your doctor tells you it's okay.

Radiation therapy kills cancer cells. But it also harms healthy cells nearby. This can cause effects on skin that look like a mild sunburn or worse. This is sometimes called radiation dermatitis. These effects include:

• Dryness.
• Itching.
• Redness.
• Swelling.
• Peeling.
• Tanned skin.
• Blistering.

Most skin reactions will heal 1 to 3 weeks after radiation therapy treatments have ended. Sometimes treated skin will stay darker. It may be more sensitive than it was before treatment.

• Wear loose clothing. This will help prevent rubbing on sensitive skin.
• Gently clean your skin daily with warm water and mild soap, or as advised. Use soap that has no fragrance added. Use your hands instead of washcloths or sponges. Pat your skin dry.
• Check with your doctor before shaving skin in the treated area. They may advise using an electric razor. Or they may tell you not to shave to prevent irritation.
• Don't use tape, lotion, body oils, perfume, deodorant, hair removal products, or powder in the treatment area. Your doctor may have different instructions for you.
• Ask your doctor if you should use moisturizer on your skin. Use only creams or lotions they approve. Make sure the moisturizer is fully gone from the skin each day before the radiation. Reapply only after the radiation of the day is done.
• Don't use products that contain alcohol. These may cause dryness.
• Don't put anything hot or cold on the treated skin. These include heating pads and ice packs.
• Stay out of the sun. If you must be outdoors, wear a hat with a wide brim and clothing to protect the skin. If your doctor says it's okay to use sunscreen, use SPF 30 or higher. Be sure to protect your skin from the sun even after your radiation treatments are over.
• Talk with your radiation oncology team if you're having skin problems that don't get better or get worse after treatment has ended.
• See a dermatologist to help manage severe skin reactions, if your doctor tells you to.