CRD summary: This generally well-conducted review evaluated the effectiveness of desloratadine in the treatment of allergic rhinitis. The authors concluded that desloratadine is associated with significant beneficial effects on symptoms of allergic rhinitis as well as objective measures of nasal blockage and allergic inflammation. The conclusions are consistent with the results reported and are likely to be reliable.

CRD commentary: The review addressed a well-defined question in terms of the participants, intervention and outcomes. Relevant databases were searched without language restrictions, thereby reducing the risk of language bias. However, some relevant studies might have been missed as no specific attempts were made to identify unpublished studies. The review methods were well-described and included measures to avoid the introduction of bias. The methodological quality of the studies was assessed using validated methods. The authors did not describe how the data from crossover trials were handled and combined with the data from parallel-group design trials. Some appropriate subgroup analyses were carried out. Overall, this was a well-conducted review and the conclusions are likely to be reliable.