The objective of this study was to evaluate the prevalence of skin test sensitivity to Blatella germanica, Blatta orientalis, upella longipalpa, Periplaneta fulliginosa and Periplaneta australiasae in patients with rhinitis and/or asthma living in Rosario, ARGENTINA.

A total of 102 patients (55 females, 47 males; mean age 27.2 years) were evaluated in two private clinics and in one public Hospital; 22.5% had asthma, 40.2% rhinitis and 37.3% rhinitis and asthma. A questionnaire was completed by the patients, including questions about their socioeconomic status. Skin tests were conducted with extracts of B. germanica, B. orientalis, S. longipalpa, P. fulliginosa, P. australiasae and a battery of common aeroallergens (C.B.F. LETI).

A positive skin test was recorded in 94 patients (92.2%), 96.8% of which were positive to mites, 25.5% to pollens, 17% to moulds, 8.5% to epithelia and 46.8% to at least one of the cockroach species tested; 34.1% of these patients was sensitized to all 5 cockroaches and 18.2% were sensitized to just one species. The prevalence of sensitization to the respective species was: 29.8% to B. germanica, 31.9% to B. orientalis, 29.8% to S. longipalpa, 30.9% to P. fulliginosa and 24.5% to P. australiasae. No significant differences in the prevalence of sensitization were detected in the different socioeconomic levels or by type of disease.

There is a high prevalence of sensitization to cockroaches in allergic patients in Rosario, Argentina, which is not dependent of the socioeconomic status of the patients. A variable degree of cross-reactivity among these cockroaches was detected.