Parietaria pollinosis: clinical and epidemiological aspects

The aim of our study was the evaluation of clinical and epidemiological aspects of P pollen allergy, which is a very frequent cause of respiratory allergy in the Mediterranean area, in a homogeneous group of 442 monosensitive subjects (235 females and 207 males, mean age about 30 years) living in Naples. All patients underwent the following diagnostic procedures: anamnestic evaluation with an internal questionnaire, physical examination, SPT with commercially available allergenic extracts (DHS-Bayropharm Milan Italy); sNPT, NsBPT, and serum specific IgE determinations were also carried out in three groups of 50 different subjects. The results of our study show a highly relevant intensity of SPT positivity (4+ and 3+ in about 95% of patients). The age of onset of clinical symptoms ranged between 20-25 years, and the majority of P monosensitized patients were born in the spring months, with an early exposure to P allergens. Rhinoconjunctivitis and bronchial asthma, alone or association, represent the most common clinical manifestation of this allergy. The season in which patients experience clinical symptoms is prevalently spring (75, 12%). However, many people show a multiseasonal pattern (18, 55%). The frequency of SPT positivity to P allergens is increasing in the last 15 years, probably due to increased urban air pollution. In conclusion, the results of this study demonstrate the high frequency and severity of this pollinosis and seem to confirm some epidemiological aspects connected with other allergenic pollens (birth during the seasonal period of pollination and association with a high urban air pollution).