About Radiation Dermatitis
Who gets radiation dermatitis?
Radiation dermatitis is the name for the skin reaction resulting
from exposure to radiation, and is a side-effect of radiotherapy.
Around 60% of cancer patients receive radiotherapy. This involves
repeated exposure of the tumour area to radiation over a period
of about 4 to 6 weeks. The goal of radiotherapy is to kill the actively
growing tumour cells. Unfortunately this cannot generally be achieved
without damaging the normal skin overlying the tumour, because the
lower layers of the skin are made up of actively growing cells which
are also susceptible to damage from radiation.
What is radiation dermatitis?
The skin reacts to the radiation by setting off a chain reaction,
whereby the lower layers of the skin become reddened and inflamed.
Free radicals, chemicals which can further damage the skin, are
produced during the skin’s reaction to radiation. Damaged
cells release enzymes into the wound environment, which cause further
deterioration of the irradiated area by degrading components of
the skin structure.
As the lower layers of dividing skin cells have been killed, the
irradiated skin cannot immediately produce new skin layers. The
surface of the skin can flake off if it dries out, leaving the lower,
moist skin layers exposed (“moist desquamation” or “skin
breakdown”). The wound is then vulnerable to infection and
must be protected with dressings. It can also be quite painful.
Progression of the condition depends on the total radiation dose,
fractionation, total duration of treatment, volume of tissue irradiated
and the energy and type of radiation delivered1. The
most serious stages tend to occur in the first few weeks after radiotherapy
has ceased.
Longer term effects
Healing can take several weeks, and the affected skin may never
fully recover. The skin can become lighter than the surrounding
skin as pigmented cells are damaged, and may have a pitted appearance
where the collagen structures of the skin have been damaged. Spidery
red lines (telangiectasia) can appear where tiny blood vessels have
been damaged. The skin may also heal more slowly if further skin
damage occurs in the same area.
Goals of treatment
The goal of treatment of radiation dermatitis is to prevent skin
damage as much as possible in the first place, and to minimise deterioration
of irradiated skin. This is especially important in areas that are
difficult to cover with dressings, such as earlobes or skin folds
(e.g. under the breasts, in patients with breast cancer).
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