Study for the Treatment of Persistent Allergic Rhinitis With Desloratadine (Study P04684)

Inclusion Criteria: * For this study, the diagnosis of persistent allergic rhinitis (PER) is not based solely on the current episode of allergic rhinitis (AR). Subjects must have at least a 2 year history of AR consistent with PER (defined as symptoms of allergic rhinitis present more than four days per week and for more than four consecutive weeks per year); the current episode can count as the second year. * Subjects must be 12 years of age and older, of either sex and of any race. * At the Run-in Visit, subjects must be sufficiently symptomatic, with a T5SS 12-hour AM-PRIOR (Subject's Status Over Previous 12 Hours) symptoms severity score of at least 8. * In order for a subject to qualify at the Baseline Visit, the sum of the daily averages of the diary recordings of the 12-hour AM PRIOR + PM-PRIOR T5SS collected during Days -4 to -1 and the AM PRIOR T5SS on the morning of the Baseline Visit (Day 1) must be \>=40. * Subjects must have a positive skin-prick test at screening to one or more allergens in the Global Allergy and Asthma European Network (GA2LEN) (or the usually used local) panel of seasonal and perennial allergens. Subjects must demonstrate an antigen-induced skin prick wheal at least 3 mm in diameter greater than diluent control. The positive tests must include the allergen(s) prevalent while this study is active. * Subjects must be free of any clinically significant disease, other than PER, which would interfere with the study evaluations. * Subjects, or pare…