Skin Reactions

Skin reactions refer to redness and irritation similar to a sunburn, a rash, or dry, flaky skin. These reactions often cause itchiness and discomfort and may be embarrassing when the reaction is on the face. Skin reactions are usually mild to moderate but can become severe if not treated early. It is important to note that skin reactions are side effects of treatment, not an allergic or infectious reaction.
 

People treated with radiation therapy are most likely to have a skin reaction in the area of the body being treated. Skin reactions occur in most people taking targeted therapy drugs. Skin reactions from targeted therapy usually start as a redness or warm sensation (as with a sunburn) on the face and upper body that develops into a rash. The rash resembles acne, with tender pimples and pus bumps. Some cancer drugs can cause a photosensitivity of the skin — an inflammation of the skin caused by the combination of sunlight and certain medications or substances — that leads to redness of the skin similar to sunburn.
 

With radiation therapy, skin reactions are caused by small amounts of radiation that are absorbed by the skin in the area being treated. Targeted therapy drugs act by blocking specific molecules in cancer cells. These molecules are also important for the normal growth of skin cells, and blocking them can cause reactions.
 

Skin reactions with radiation therapy begin about 2 to 3 weeks after the first treatment and will typically resolve within a few weeks after treatment ends. In some cases, the treated skin may stay darker than it was before. With targeted therapy, a rash most often starts within the first few weeks after taking the drug and resolves about 1 month after treatment is stopped.
 

Skin reactions caused by radiation therapy are usually minor and do not require treatment. Reactions caused by targeted therapy drugs range from mild to severe. Rashes that are in a limited area, that do not cause discomfort and are not infected usually do not need to be treated. If the rash spreads over a larger area and causes itchiness or pain, your doctor may prescribe a mild corticosteroid cream (hydrocortisone) or an antibiotic gel (clindamycin gel). These creams are also used for severe rashes, or rashes that cover a larger area of the skin, are very itchy and/or painful, and are likely to become infected. In addition, severe rashes are usually treated with an oral antibiotic and perhaps an oral corticosteroid, such as methylprednisolon (Medrol) or prednisone. When a rash is severe, the dose of the targeted therapy drug is often reduced or restarted if the rash gets better within 2 weeks.

People who are being treated with either radiation therapy or targeted therapy should follow some general measures to take special care of their skin and to ease discomfort from reactions.
 

Skin Care: Do's and Don’t
 

You should talk to your doctor before radiation therapy or targeted therapy begins about the possibility of skin reactions. You should tell your doctor or nurse about any reactions as soon as they appear, as early treatment can prevent the reaction from becoming severe.

Do not treat your skin with over-the-counter medicines or stop taking your targeted therapy drug without talking to your doctor first.
 

• American Cancer Society: www.cancer.org, Coping with Physical and Emotional Changes: Dealing with Skin Problems
• American Society of Clinical Oncology patient Web site: www.cancer.net, Skin Reactions to Targeted Therapy
• National Cancer Institute: www.cancer.gov, Radiation Side Effects and Ways to Manage Them: Skin Changes, Managing Radiation Therapy Side Effects: What to Do about Mild Skin Changes