Respiratory allergy to Parietaria pollen in 348 subjects

We have revisited 348 records of allergic outpatients to Parietaria, ratio M/F 1:1 and mean age 29.46 ± 12.49 yrs. 97 of them were skin positive to Parietaria only (A-group: M/F 37/60); 251 patients were skin positive also to other allergens (B-group. M/F 137/114). Mean age of A-group patients (35.41 ± 12.91) was higher than B-group (27.16 ± 11.54; p< 001). Dividing mono and polysensitized subjects by age decade, a different distribution was found between the two groups (p< 001): monosensitized patients showed an increasing number of subjects from the 3rd to the 4th decade and a decreasing trend in the following decades; polysensitized patients showed a prevalence in age < 20 yrs and a decreasing trend in the other decades. In B-group Gramineae were the most frequent allergens associated to Parietaria (84.8%) followed by Olea Europaea (41.1%), Dermatophagoides farinae (37.4%) and Dermatophagoides pteronyssinus (36.2%). Main symptoms were rhinoconjunctivitis (187 cases), rhinitis + asthma (141 cases) and bronchial asthma (20 cases). Comparing the clinical features of the two groups, we have found that monosensitized patients showed a female prevalence, a prevalence of rhinitis with late onset of symptoms while in patients suffering from isolated asthma the onset was early.