Parietaria allergy in children.

Parietaria, a grassy plant belonging to the Urticaceae family which is commonly found in urban environments, tends to grow on fences, walls and soils with a high content in nitrogen. Since 1983 the Xarxa Aerobiologica de Catalunya (Catalonian Aerobiological Network) has been using Hirst and Court sensors to monitor the daily concentrations of its pollen with respect to the weather conditions (wind, rain, temperature) in various sites in Catalonia and the Balearic Islands. This pollen is present practically all year round in our area, mainly during cold, rainy and seaside areas. Studies at a pediatric level are scarce and this is why we reviewed our data in this field. The study included a total of 12,650 case histories of first time attendances to our Pediatric Allergology Unit; 449 children showed sensitivity to Parietal pollen. Exclusive sensitivity to Parietaria in this age group of 1 and 15 years olds tended to be very low. However, we observed that after initial preferential sensitization to domestic allergens, Parietal pollen became the most frequent cause of sensitivity as the patients grew older. Although rhinoconjunctival manifestations predominate, at least at a pediatric level, the implication of Parietal pollen as a cause of bronchial asthma cannot be ignored.