Mosquito bite: an emergent allergen in the Mediterranean area?

Introduction: Mosquitoes are a family of insects of the order Diptera, whose bite is usually followed by a local reaction. In some cases, the local reaction can be severe and systemic reactions have been rarely reported as well. Allergic reactions to mosquito bite are underestimated due to the current lack of reliable diagnostic tools. In addition, the new study done by Scala et. al suggests the possible existence of a "bee-mosquito syndrome". ?Few studies have been conducted on Culex pipens and no molecule has been registered to date in the WHO/IUIS database. Material and methods: 5 individuals reporting large local reactions to mosquito were enrolled and studied for cutaneous and sIgE reactivity to mosquito, Penaeus monodon, Dermatophagoides pteronyssinus, Dermatophagoides farinae and Pen a1. Immunoblot (IB) analysis with a purified in-house extract of Culex pipens and Aedes albopictus (all body and thorax) were carried out. Results: 5/5 were sIgE positive to mosquito, 5/5 were sIgE to Penaeus monodon, 3/5 were sIgE to Dermatophagoides pteronyssinus e farinae, 1/5 was sIgE to Pen a1. On IB analysis, IgE reactivity was recorded in sera from 5/5 patients at the following KDa: between 25-37 KDa, 50-75 KDa, 75-100 KDa, 150-250 KDa in all body and thorax of the two species. Bands between 25-37 KDa might be similar to Aed a 2, Aed a 5 and Aed a 10 allergens from Aedes aegypti. Bands between 50-75 KDa might be similar to Aed a 1 and Aed a 4 allergens. Bands between 75-100 KDa might be the same as Api m 5 (Apis mellifera) and Pol d 3 (Mediterranean paper wasp) allergens from Hymenoptera. Band between 150-250 KDa might be similar as Api m 12 from Apis mellifera. Conclusions: this is the first time that bands of high KDa, similarly to some Hymenoptera allergens, have been described in a purified in-house mosquito extract. IB with mosquito extract and Hymenoptera extract will be done to confirm our hypothesis.