[Pollinosis in Canton Ticino. A prospective study in Locarno].

A study was carried out in the southern part of Switzerland (Canton Ticino) in 1990-1993 to determine the spectrum of cutaneous sensitivity to a large amount of pollens and several perennial allergens (50), using skin prick tests in a sample of 503 consecutive patients suffering from hay fever. The Canton Ticino is a very specific geographical and botanical area which includes several plants of the alpine and Mediterranean flora as well as representatives of the tropical flora, forming a unique pattern from a botanical and allergological point of view. The results of the study indicate that in this region the patients have symptoms of hay fever almost 10 months a year (from December until October) with a peak in May and June (88% and 73% of the patients respectively have symptoms in these months). The symptoms are mainly localized in the upper respiratory tract and eyes. Asthmatic symptoms were found in about 23% of the patients. At the top of the allergen list were grass-pollens (72% of the patients had sensitivity); rye (69%); olive tree (54%); birch (46%); chestnut (37%); ash tree (36%); alder tree (33%); ragweed (17%); parietaria (18%). Of real interest in this study area are, besides the classical allergy-inducing pollens, those of chestnut, parietaria, olive tree, ash tree and cupressaceae (for example cypress). Chestnut pollens represent about 30% of the airborne pollens in this region. 30% of the patients had sensitivity against dust mites (Dermatophagoides pteronissimus und D. farinae), and 20% against cats. Sensitivity against 8 mould spores was 2-9%.