Processionary caterpillar reactions in Southern Italy forestry workers: description of three cases

BACKGROUND: Processionary caterpillar (PC), also named Thaumatopea pityocampa, has been reported to cause hypersensitivity reactions after contact with a toxin contained in hair-like bristles which cover this insect. Occupational exposure to PC is underestimated in outdoor workers and especially in forestry workers (FW) and is globally diffusing because of rising temperatures. CASES PRESENTATION: We present the first three cases of FW from Sicily, a Southern Italy (SI) region, which reported hypersensitivity reactions due to exposure to PC infested trees. These cases were identified by the occupational health physician during the annual screening of FW working in the Mountains of north-eastern Sicily. Interviewing a population of 630 FW, 1 male and 2 females reported direct contact skin reactions together with airborne contact reactions to PC hairs causing mild respiratory symptoms in two cases and ocular symptoms in one case, which needed treatment with systemic corticosteroids and antihistamines. CONCLUSIONS: This is the first report of hypersensitivity reactions in SI FW due to occupational exposure to PC. Further screenings not only in FW but also in other populations of outdoor workers are needed in order to assess the real incidence of contact and airborne reactions due to occupational exposure to PC. Though so far no correlation has been found with atopy, it seems apparent that the reactions occur in susceptible subjects; further research is needed for a correct diagnosis and to identify possible desensitization procedures.