Acute radiodermatitis from accidental overexposure to X-rays.

Approximately 2 weeks after accidental overexposure to X-ray radiation, a worker developed acute radiodermatitis on fingers of both hands. Exposure simulation indicated that total ionizing radiation absorbed by his fingers amounted to about 20 Gy. After 2 years, acute radiodermatitis evolved to chronicity of lesions with presence of atrophic skin, teleangiectasia, alopecia, and dyskeratosis on three right-hand fingers. Cytogenetic dosimetry of peripheral blood lymphocytes, performed 2 months after acute radiation, showed an increase of micronuclei (7% vs. 1 +/- 0.4% according to laboratory reference data). The increase was ascribed to the high dose of ionizing radiation absorbed by circulating lymphocytes in the vessels of overexposed tissues. The cytogenetic examination was repeated 27 months after acute irradiation; it was found that the percentage of micronuclei had been restored to within reference levels. The possibility of using cytogenetic dosimetry, following acute partial exposure to X-rays, not just as an indicator of previous exposure, but also as an indicator of the absorbed radiation dose is examined. Lastly, the possible stochastic effects that may set in on the skin of the affected fingers and the need for periodically monitoring the evolution of chronic skin lesions, are discussed.