Hymenoptera sting reactions in southern Italy forestry workers: our experience compared to reported data.

Background: Hymenoptera sting reactions are among life-threatening causes of allergy. Several epidemiology studies have assessed the risk of these kind of reactions, among the general population, around 3% of adults. This incidence increases among highly at risk populations such as outdoor workers. Hymenoptera stings among forestry workers (FW) are occupational triggers but it has not yet been well defined which is the real incidence of anaphylaxis in these workers, not even in Italy. Two Italian studies reported on the risk of hymenoptera stings (HS) in northern Italy (NI) and central Italy (CI) FW while no data is available on the prevalence in southern Italy (SI) ones.

Methods: A population of 341 SI FW (301 males and 40 females, mean age 51 years, range 43-63 years), who worked in Sicily, was investigated submitting a standardized questionnaire dealing with reactions to Hymenoptera stings, such as large local reactions (LLR) and systemic reactions (SR).

Results: HS occurred in 203 FW (59%) and caused reactions in 77 (22%); LLR occurred in 46 (13%) and SR in 31 (9%); SR were life threatening in 9/341 (3%) FW and were treated with epinephrine at the emergency unit as workers did not carry an epinephrine auto-injector. A SR at a subsequent HS followed a LLR in 21/46 FW (46%).

Conclusions: FW in SI have a generic risk of HS anaphylaxis as in the general population but a higher risk of SR and LLR respect to forestry populations from different Italian geographical areas.SR among SI FW occurred in 9% of them, while published data report the incidence of SR around 2 and 4%, respectively, in the Centre and North Italy FW. The incidence of LLR in SI FW was also higher (13%) than in CI (2%) and NI (10%) ones. Previous LLR in our SI population represented a high risk factor for developing a SR and therefore a red flag for future anaphylaxis and prescription of an epinephrine auto-injector.