Mioga (Zingiber mioga Rosc.) is a member of the ginger family (Zingiberaceae), which is native to tropical Asia. In Japan, the young flower buds are used as a spice, and hand dermatitis suspected as being an allergy to mioga has been recognized in mioga greenhouse cultivators. To investigate the extent of the problems and the causes of dermatitis, 20 householders cultivating mioga in their greenhouses were asked to participate in a questionnaire study. Consecutive patch tests were performed on some subjects with dermatitis. Self-reported questionnaires were distributed to the main cultivator in each household who attended a lecture of mioga cultivation methods held at an agriculture cooperative association in the area. Some subjects who answered as presenting or having had hand dermatitis were patch tested for mioga (as is), four kinds of mioga extracts, and three kinds of natural rubber gloves.
Results: 35 cultivators from 16 households answered the questionnaire. Eight of the 35 subjects (22.9 percent) answered that they had experienced hand dermatitis since they started mioga cultivation. Four of the 8 subjects were patch tested. Two of the 4 subjects showed allergic reactions to mioga (as is) and the extracts. The other two cases showed irritation to mioga (as is). The first two cases also showed allergic reactions to natural rubber gloves. To our knowledge, there is no previous report of allergic contact dermatitis from mioga.