Was kommt dort durch die Luft geflogen …?: Die Gefährdung des Menschen durch die Gifthaare des Eichenprozessionsspinners

Fourth to sixth instar larvae of the oak processionary moth protect themselves against predators by urticating hairs (setae). Setae may cause inflammatory reactions on skin as well as on mucous membranes (lepidopterism), both in humans and animals. People may get in touch with setae by direct contact or – more frequently – airborne. Frequency of lepidopterism is high due to the fact that the oak processionary moth infests the urban green, especially in years with mass gradation. Lepidopterismus, however, is under-diagnosed. In seasons of toxic larvae, doctors should therefore consider lepidopterism a differential diagnosis in patients with asymmetrically distributed, itchy papular rash or wheal formation. Preventive measures are avoidance of infested areas and use of protective equipment by outdoor workers at risk.