Sensitization to Cat: When Is Nasal Challenge Needed?

Introduction: Although the skin prick test (SPT) is a reliable diagnostic tool in perennial allergic rhinitis (PER) for patients allergic to cats, the minimum necessary SPT wheal size required to distinguish cat sensitization from true allergy remains controversial. The cat nasal challenge test (cNCT) could be considered the gold standard for detecting true cat allergy.

Aims: To assess the difference in the frequency of cNCT positivity between cat owners and non-owners and to determine an appropriate cut-off level for SPT wheal size in detecting positive cNCT in PER patients who are candidates for allergen immunotherapy (AIT) with cat allergen extracts.