Prick puncture skin tests and serum specific IgE as predictors of nasal challenge response to Dermatophagoides pteronyssinus in older adults

Background: The ability of prick puncture skin test (PPST) results and the presence of serum specific IgE (sIgE) to Dermatophagoides pteronyssinus to predict positive or negative nasal challenge (NC) results has not been determined in older adults. Objective: To determine if allergy skin test and/or serum sIgE is diagnostic of allergic rhinitis in older adults. Methods: Forty-eight adults (20 younger and 28 older) with rhinitis underwent NC to D pteronyssinus 1 to 4 weeks after PPST and sIgE to D pteronyssinus. Patients were not aware of their in vivo or in vitro results at the time of their NC. Results: Fourteen of 48 adults (10 younger and 4 older) were NC positive. The positive predictive values for older adults with positive NC results ranged from 28.57% to 42.86% for PPST and was 16.67% for sIgE. In contrast, positive predictive values in younger adults ranged from 76.92% to 100% for PPST and was 100% for sIgE. However, negative PPST results and sIgE had high predictive values for a negative NC result to D pteronyssinus in older adults (90.48%-95.24% for PPST and 89.47% for sIgE). Conclusions: Although PPST and sIgE negative results were good predictors of negative NC outcomes, neither positive PPST results nor serum sIgE to D pteronyssinus predicted positive NC results in older adults. PPST and sIgE to D pteronyssinus were excellent predictors of both positive and negative NC outcomes in younger adults.