Prevalence and clinical characteristics of chronic urticaria and positive skin prick testing to mites.

The aim of this study was to review chronic idiopathic urticaria patients with positive skin prick testing to mites and the clinical relevance of this positivity. Case records of patients with chronic idiopathic urticaria who underwent skin prick testing during the years 2000 to 2007 were reviewed. The studied allergens included house dust mite allergens; Dermatophagoides pteronyssinus and farninae. A total of 172 patients were enrolled in the study. The prevalence of positive skin prick testing to mites among patients with chronic idiopathic urticaria was high (34.9%), but had little clinical relevance (3.3%) to their urticarial symptoms. Patients with mite-sensitization were more commonly male and more often had a personal or family history of atopy compared with those without mite-sensitization.