Different phenotypes of intermittent and persistent respiratory allergy in Zagreb, Croatia.

Allergic rhinitis (AR) is a major chronic respiratory disease because of its prevalence, its impacts on the quality of life, economic burden and links with asthma. A significant relationship between the severity of rhinitis and prevalence of asthma in allergic patients was found both in patients suffering from seasonal rhinitis and in those suffering from perennial-allergic rhinitis (PAR) and asthma. The aim of the study was to investigate allergy phenotypes in patients with intermittent allergic rhinitis (IAR) and persistent allergic rhinitis (PAR) in residents of Zagreb, and to determine if there were any other differences in the clinical (in vivo) and diagnostic (in vitro) presentations of the phenotype of subjects suffering from different types of rhinitis. 205 subjects were divided into 2 groups, 102 with IAR sensitized to ragweed pollen (Ambrosia elatior) and 103 with PAR sensitized to house dust mites (Dermatophagoides pteronyssinus and Dermatophagoides farinae). The diagnosis was based on a detailed medical history, examination and diagnostic tests (spirometry, reversibility after appliance of salbutamol, skin prick test, and total IgE). Rhinitis symptoms in subjects with IAR were significantly different than in those with PAR. Sneezing and a runny, itchy nose were frequently present in the IAR group, but not in the PAR group. Prevalence of the coexistence of asthma was higher in the PAR group (35:57%), as well as more severe clinical phenotype of asthma. The covariation of sensitization was similar (70:74%). The most frequent sensitization in the IAR group was found to house dust mite (38%), and in the PAR group to animal dander (40%). The clinical presentation of the IAR was different from that of the PAR. The prevalence of coexisting asthma was significantly higher in the PAR group. The covariation of sensitization was similar.