Allergic rhinitis diagnosis: skin-prick test versus laboratory diagnostic methods

Abstract

Aim To verify the specificity, sensitivity, and accuracy of the skin-prick tests (SPTs) in allergic rhinitis (AR) compared with blood tests and nasal smears. Study design It is a cohort, prospective, nonrandomized study. Patients and methods A total of 180 patients were enrolled. Group A included 135 patients having AR symptoms for more than 1 year. Group B included 45 patients without AR symptoms candidate for septoplasty surgery who served as controls. All patients were subjected to detailed history, scoring for AR, endoscopic examination, complete blood count, nasal smear eosinophilia, and SPT. Results SPT was positive in 94.1% (n=127) of allergic patients and 20% (n=9) of the controls at least for one allergen. Most of cases were allergic to mixed pollens (66.7%), cotton dust (41.5%), and housefly particles and house dust mite (28.9% equally). The absolute eosinophil count was positive in 70.4% of allergic patients (n=95) and 33.3% of the control (n=15). Nasal smear eosinophilia was positive in 82.9% (n=112) of allergic patients and 20% (n=9) of the controls. SPT possesses high sensitivity and specificity that reached 94.1 and 80%, respectively, and 90.6% accuracy. However, absolute eosinophil count showed the lowest results, where sensitivity and specificity reached 70.4 and 66.7%, respectively, and 69.4% accuracy. Conclusion SPT is accurate for diagnosing AR and possesses high sensitivity and specificity; however, adding a nasal swap test will raise the sensitivity, specificity, and accuracy of diagnosis.