- Has a demonstrated sensitivity to at least 1 allergen known to induce PAR (house dust mites, cockroaches, molds, and animal dander) based on a documented result with a standard skin-prick test either within 12 months prior to screening visit or performed at the screening visit. A positive test is defined as a wheal diameter at least 3 mm larger than the negative control wheal for the skin-prick test. The subject's positive allergen test must be consistent with the medical history of PAR, and the allergen must be present in the subject's environment throughout the study.