[Radiodermatitis].

All radiations that cross the skin to reach the target organ may produce dermatitis. The skin reaction essentially depends on the total dose delivered, but the fractioning of that dose and its distribution over time are important factors. As benign lesions are no longer irradiated and as accidental or occupational exposure to radiations has become exceptional, the main cause of these lesions is irradiation of malignant tumours, increasingly combined with supportive treatments. Owing to technical improvements radiodermatitis is now less frequent than formerly. Acute radiodermatitis clinically resembles burns. Chronic radiodermatitis may follow the acute phase or occur suddenly after a latent period, sometimes very long. An untractable ulceration developed on an area previously irradiated should suggest malignant degeneration which is by no means infrequent. The best treatment of radiodermatitis is prevention, but plastic surgery has progressed, and patent lesions can now be removed in one stage (skin and muscle), thus transforming the patients' life, previously made very uncomfortable by invalidating lesions.