Skin Reactions

Understanding Skin Reactions Related to Cancer

Cancer is treated in a variety of ways. Depending on your type of cancer and at what stage it was diagnosed, your treatment plan may involve surgery, radiation therapy, chemotherapy, hormonal therapy, biologic therapy or a combination of treatments. Unfortunately, dermatologic reactions to these treatments are common and can include rashes, dry and itchy skin, hair loss, mouth sores, skin darkening, photosensitivity, skin growths and changes to your hair, fingernails and toenails.

Most reactions are mild, but some can be severe. However, the more you understand about what to expect, the better you will be able to manage these side effects.

Cancer treatments work by attacking the rapidly dividing cancer cells in your body. However, many normal cells in your body, such as blood cells and cells in your mouth, nails, hair and skin, also divide rapidly. Therefore, the cancer treatments also attack them.

Skin reactions are not the only side effects you may experience with chemotherapy, but they are probably the most common. The specific side effects you experience will depend on many factors, including the types of medication you are given as well as the dose, the frequency it’s given, the length of time you take it, and your general health.

This guide discusses the main skin-related side effects you might experience during and after your treatment as well as guidance on how to manage them. Keep in mind, however, that as you go through your cancer treatment, you may experience all, some or none of the reactions included here.

When you start your treatment, make a list of the reactions you experience and when you experience them. Contact your health care team as you develop dermatologic reactions for tips on symptom management because these side effects can worsen if they are not treated appropriately. If your reactions become severe – or if they begin to affect your ability to care for yourself – contact your health care team immediately.

With appropriate side effects management, you can receive the benefits of the full cancer treatment planned for you. Here you will learn more about the anatomy of the skin as well as information about possible skin reactions and helpful hints for managing them.

Cancer treatment is not easy. But together with your oncologist and other members of your health care team, you will learn how to take care of your treatment-related side effects and improve your quality of life.

A closer look at the anatomy of the skin

To understand dermatologic reactions and side effects, you must first understand the skin – the largest organ of the body. Skin has many functions, including protecting you from sunlight and infectious germs, allowing feelings of touch and sensation, and regulating your body temperature.

The skin has three layers: the epidermis, the dermis and the hypodermis, which is a layer of fatty tissue (see Figure 1). Each layer has a different function, thickness and strength.


The epidermis is the thin, outer layer of the skin. Its outermost portion – the stratum corneum – makes the skin more or less waterproof and prevents bacteria, viruses and other foreign substances from entering the body. That’s why it’s so important to take care of your skin and make sure it does not dry out and develop cracks.

The epidermis also contains cells called melanocytes. These cells produce a pigment called melanin, which gives your skin its color and blocks the damaging ultraviolet rays of the sun. Because it covers the entire body, the epidermis also helps protect internal organs against any injury.


The dermis is the layer of skin underneath the epidermis and gives the skin its flexibility and strength. Nerve endings, sweat and oil glands, hair follicles and blood vessels are all present in this second layer:

  • Nerve endings provide sensations of touch, pain, pressure and temperature.
  • Sweat, produced by the sweat glands, is a mixture of chemicals with salt and water. Sweat helps cool the body when it evaporates.
  • Oil glands keep the skin moist.
  • Hair follicles are the source of hair on the body.
  • Blood vessels of the dermis provide nutrients to the skin and help regulate body temperature.

Hypodermis (fatty tissue)

The hypodermis is the layer of skin underneath the dermis. It is composed of fat cells, which help protect your body from heat and cold. This layer also serves as a place to store energy and provides protective padding for the internal organs. Its thickness can vary from a fraction of an inch at the eyelids to several inches at the buttocks.

When you begin cancer treatment, you will likely experience many changes in your skin. To best protect it from potential side effects, talk to your health care team and follow simple preventative measures (see below).

Skin care suggestions

Do Don't
Wash skin with lukewarm water. Wash skin with hot water.
Take baths. Take showers.
Use mild soap that does not contain alcohol, perfume or dye. Put anything hot or cold on the affected area, such as heating pads or ice packs.
Use oatmeal products designed to soothe the skin. Use anti-acne skin products containing alcohol, benzoyl peroxide or retinoids.
Dry skin by patting it gently with a soft towel. Rub skin with a washcloth or towel.
Moisturize your skin twice a day with a thick cream that contains no alcohol, perfume or dye. Apply the moisturizer while your skin is still damp after bathing. Rub or scratch sensitive areas.
Use an electric shaver if shaving is necessary, but first check with your doctor or nurse. Use a razor blade to shave.
Use paper tape if bandaging is necessary. Use adhesive tape if bandaging is necessary.
Wear loose-fitting clothes. Wear tight-fitting clothes.
Use gentle laundry detergents, free of perfumes or dyes. Starch your clothes.
Protect your skin from the sun during treatment and for at least one year after the end of treatment. Go out in the sun without protective clothing or a wide-brimmed hat and sunscreen, or use tanning beds.