Sensitization to cockroach allergens in a sample from the urban population living in Naples (southern Italy).

The aim of this study was to evaluate the prevalence of allergic sensitization to cockroach allergens in a group of atopic patients living in the urban area of Naples. Four hundred and fourteen consecutive patients were submitted to the following diagnostic procedures: anamnestic data; clinical examination; and skin prick test by using a standardized pricker and allergenic extracts, one of which contained a mix of whole bodies of Blattella orientatis, Blattella germanica and Periplaneta americana. The evaluation of cockroach serum specific IgE antibodies was carried out in the 19 patients (4.58%) who showed a positive skin prick test to cockroach allergens. The majority of cockroach sensitive individuals were males and exhibited perennial respiratory symptoms; 17 of these patients were also sensitized to Dermatophagoides pteronyssinus allergens. The results of our study demonstrated that the prevalence of cockroach sensitization as determined by skin prick test in our urban area (Naples) is lower in comparison to other European studies. Up to now, it is not clear if the association between cockroach-D. pteronyssinus sensitization can be determined by a cross-reactivity between the allergens or by their coexistence in the same indoor environments. Considering the absence of a visual presence of cockroaches in the indoor environments of our cockroach-sensitive patients we suggest the possibility of unrecognized exposure to cockroach materials and, moreover, the possibility of the carrying of such allergens from infested places on clothing, as we demonstrated for Fel d I.