[A study on the estimation of prevalence of epidermolysis bullosa in Japan]

An estimation of the prevalence of epidermolysis bullosa was carried out in Japan. A questionnaire was sent by mail to the departments of dermatology and pediatrics in 644 main hospitals throughout Japan requesting confirmation of the number of epidermolysis bullosa cases experienced. The response rate was 63.0% or 406 hospitals. Based on the secondary questionnaire survey, we confirmed 393 cases of epidermolysis bullosa, and then divided them into the five following groups: "simplex" type 182 (48.2%), "junctional" type 23 (6.0%), "dominant dystrophic" type 72 (18.7%), "recessive dystrophic" type 109 (28.2%), unclassified 7 (1.8%). Using the respondent rate by geographic region and clinical department, the estimated prevalence of each type of epidermolysis bullosa was calculated as follows: "simplex" type 340-470 (0.29-0.40 per 100,000 population), "junctional" type 18-24 (0.015-0.020), "dominant dystrophic" type 130-180 (0.11-0.15) and "recessive dystrophic" type 180-250 (0.15-0.21). The total number of epidermolysis bullosa patients in Japan was estimated as being more than 670 in 1983.