​Dermatology - Radiation Dermatitis

​Dermatology - Radiation Dermatitis
Radiation dermatitis refers to alterations in the skin caused by exposure to ionizing radiation.
The types of radiation that can cause radiodermatitis include superficial and deep x-ray radiation, electron beam therapy, and Grenz ray therapy.

The reversible effects include discomfort, redness, hair loss, inhibition of sebaceous glands, and changes in skin color that can endure for varying durations, ranging from weeks to months to years. The irreversible consequences include atrophy, sclerosis, telangiectasias, ulceration, and the development of radiation-induced malignancies. Chronic radiation dermatitis is a condition that is enduring, advancing, and cannot be reversed. The onset of squamous cell carcinoma typically occurs within a range of 4 to 40 years, with a median duration of 7 to 12 years. Approximately 25% of cases experience tumor metastasis, even after undergoing intensive surgical procedures. The forecast is unfavorable, and relapses are frequent.

Basal cell carcinoma can also develop in cases of persistent radiation dermatitis, primarily affecting people who have been excessively exposed to x-rays. The onset of tumors may manifest approximately four to five decades following exposure.
Abnormalities
Initially, there is a transient redness that lasts for 3 days, followed by a sustained redness that reaches its maximum intensity after 2 weeks and causes discomfort. Pigmentation becomes visible around day 20. A delayed onset of redness, known as erythema, may also manifest between day 35 and 40, persisting for a period of 2 to 3 weeks. Intense responses result in the formation of large reactions, characterized by blistering, erosions, and ulceration. These reactions are painful and might occur as a recall phenomena. Long-lasting scarring can occur. 

Following a course of fractional but rather intense therapy with total doses ranging from 3000 to 6000 rad, an epidermolytic reaction occurs within 3 weeks. This reaction is then resolved between 3 to 6 weeks. Subsequently, scars and hypopigmentation emerge, accompanied by the complete loss of skin appendages and the degeneration of the epidermis and dermis. Over the course of the next 2-5 years, there is a progressive increase in tissue degeneration. This is accompanied by both excessive and insufficient pigmentation (poikiloderma) as well as the development of dilated blood vessels (telangiectasia). Necrosis and painful ulceration are infrequent but can arise from inadvertent exposure or dosage errors. The necrosis exhibits a leathery texture, yellow coloration, and strong adhesion, while the surrounding skin is characterized by intense discomfort. Ulcerations have a pronounced inclination towards inadequate healing and typically necessitate surgical intervention. Finally, there can be the presence of radiation keratoses and squamous cell carcinoma. The nails exhibit longitudinal striations, thickness, and dystrophy.


The diagnosis is established through clinical assessment, which involves evaluating the patient's medical history and examining their skin for any relevant signs.
Excision and grafting can be performed as a preventive measure prior to the onset of malignancy.