Inclusion and exclusion criteria
The inclusion criteria for studies were as follows: reporting the prevalence of urticaria in patients with rhinitis; reporting the prevalence of rhinitis in patients with urticaria; and reporting the association between rhinitis and urticaria. No restrictions on the study design type and type and/or definition of rhinitis and urticaria were applied. The exclusion criteria were a population size <50 patients and studies written in a language other than English.