A woman looks at a patch of red, dry skin on her shoulder.

Radiation: Let's Talk Side Effects

Every treatment comes with its own set of side effects.

The side effects of radiation therapy

Radiation-induced side effects are thought to be terrifying burns and mutations from nuclear fallout. This misconception deters so many patients from receiving treatment. To clear up some of the confusion, let's break down the more common side effects of radiation. To do this, let's put radiation-induced side effects into two categories: acute reactions and latent reactions.

Acute reactions of radiation therapy

Acute reactions are those that occur within 90 days from the first treatment. These are extremely common to experience while undergoing radiation therapy. As the skin cells are hit with radiation, they need time to repair. As the dose received increases, the damage increases, and the healthy cells cannot fix it as fast.

Can we avoid that damage?

So why do we not just space out the treatments more and give the healthy cells are time? We could, but that would also provide the skin cancer cells more time to repopulate. Therefore we continue the treatments knowing that even though the healthy skin is being affected, it will ultimately heal over time and eventually repair the damage.

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The common acute side effects

Acute side effects we typically see while doing superficial radiation treatments are erythema, dry desquamation, some oozing of the skin, and mild ulceration.


This is kin redness caused by inflammation. Usually, redness is the first side effect to appear. The reddening is caused by swelling of the capillaries that cause an increased blood flow to the skin.

Dry Desquamation

Dry desquamation is the shedding of the epidermis. More commonly referred to as dry, flaking, and peeling skin.

Moist Desquamation

As the skin sheds, it can become thin and lose its integrity and begin to weep fluid. The skin appears open and should be kept clean to protect from infection.

Latent reactions of radiation therapy

Latent (or chronic) reactions are side effects that can appear 90 days after the first dose of radiation. Every patient is different and there is no guarantee that someone will or will not experience latent side effects.

How we lower the risk of experiencing side effects

As providers, we carefully prescribe the amount of radiation being delivered and the timespan that the treatments occur within. We do this to lower the chance of the patient experiencing these side effects. With that, there are always exceptions.

The common latent side effects

Latent side effects patients may experience after radiation therapy are skin atrophy, telangiectasia, or pigment changes.

Skin atrophy

Skin atrophy is the thinning of the skin. Someone who experiences skin atrophy may notice a need to be more gentle with the skin as it may be more sensitive and susceptible to injury. In extreme cases, medical attention is necessary.


More commonly known as "spider veins," these are small blood vessels dilated at the skin’s surface. In most cases, these are a cosmetic concern, and most are treatable with injectables or laser therapy.

Pigment changes

There are two types of pigment changes: hyperpigmentation and hyperpigmentation.


Hyperpigmentation is the darkening of the skin. Typically this is a response to the inflammation of the radiation treatment. Darkening in color naturally fades once treatment has concluded, just as a tan from exposure to the sun. Creams and laser therapy can aid the fading of pigment.


Hypopigmentation is the loss of color. The lighter appearance is most commonly noticed in patients with red undertones or freckled appearance. The constriction of the vessels and the elimination of sun damage may cause the treated area to appear lighter than the area around it. Hypopigmentation is a cosmetic concern and can be treated with laser therapy to even out the complexion.

This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The SkinCancer.net team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

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