Clinical and immunologic surveys of Hymenoptera hypersensitivity in Japanese forestry workers.

Background : The increased incidence of bee-sting allergy among beekeepers is well known, whereas Hymenoptera hypersensitivity among forestry workers, who are frequently stung by Hymenoptera, is not well understood. Objective : To elucidate the nature of Hymenoptera hypersensitivity among forestry workers and analyze the mechanism involved in Hymenoptera-induced systemic reactions. Methods : A questionnaire was administered and yellow jacket venom-specific IgE antibody titers measured in 323 forestry workers and 100 age-matched office workers with little occupational exposure to Hymenoptera stings as a control group. Results : From the questionnaire it was found that the percentage of systemic reactions to Hymenoptera stings was significantly greater in the forestry workers than in the control subjects (P <.01). The number of sting exposures was significantly higher in the forestry workers than in the control subjects (P <.01) and was closely correlated with episodes of systemic reaction. Yellow jacket venom-specific IgE antibody titers were significantly higher in forestry workers with episodes of systemic reaction compared with those with only local or large local reactions to Hymenoptera (P <.05), although more than half of these subjects had undetectable IgE antibody titers to yellow jacket venom. IgE antibody titers against yellow jacket venom were closely correlated with those of paper wasp (r s =.802, P <.001), which is another frequent source of Hymenoptera stings. In workers with episodes of sting exposure within the most recent 3 years, the period from the last sting was not correlated with yellow jacket venom-specific IgE antibody titers. Conclusions : The number of sting exposures may contribute to systemic reactions to Hymenoptera sting, and some mechanism other than IgE mediated hypersensitivity may also be involved in Hymenoptera-induced systemic reactions.