tretinoin and Radiodermatitis

Topics: Acne Vulgaris; Carcinoma, Squamous Cell; Diagnosis, Differential; Follow-Up Studies; Humans; Laryngeal Neoplasms; Male; Middle Aged; Neck; Radiation Dosage; Radiodermatitis; Radiotherapy; Risk Assessment; Severity of Illness Index; Tretinoin

The area of UV erythema produced by a small beam head was found to increase with increasing doses. The aim was to investigate whether measurement of the area could be a more useful indicator of UV-induced damage than classic visual grading. Topical pretreatment with all-trans retinoic acid (tretinoin) and betamethasone valerate was used to test the applicability of the method in pharmacological studies. We used a round outlet head (5 mm2) connected by optical fibre to a monochromatic irradiator, and doses ranging from 0.05 to 0.2 Joule of 300 mm UV light were applied to the skin of 6 healthy subjects. Erythemal area was calculated by the measurement of two diameters, and intensity was graded visually (0-6 scale). The area of the erythema correlated with the increase in intensity up to score 6. Area measurement was less subject to intra-investigators' variability than the intensity score. By multiplying intensity by area, a good indicator of UV-induced reactivity was obtained. Pretreatment with betamethasone valerate decreased the area of erythema, as did tretinoin 12 h after irradiation. Thus, area measurement of erythema is a useful adjunct to visual grading of UV-induced skin reactions.

Topics: Administration, Cutaneous; Adult; Analysis of Variance; Betamethasone Valerate; Erythema; Female; Humans; Male; Pilot Projects; Radiation Dosage; Radiation Tolerance; Radiation-Protective Agents; Radiodermatitis; Skin; Tretinoin; Ultraviolet Rays