RESUMO
OBJECTIVE: To compare and determine the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of nasal smear eosinophilia and serum IgE levels for the diagnosis of allergic rhinitis (AR). STUDY DESIGN: Analytical study. PLACE AND DURATION: ENT and Pathology Departments, KEMU/Mayo Hospital, Lahore from January 2018 to December 2019. Methodology: Two hundred and twenty-one patients presenting with recurrent rhinitis were included in the study. They were divided into two groups: group 1 presented with history suggestive of allergy for more than four weeks and confirmed to be AR on skin prick tests; group 2 patients with negative skin prick tests taken as controls. Both groups were subjected to serum IgE levels and nasal smear for eosinophilia. Prick test was taken as gold standard, and p<0.05 was taken statistically significant. RESULTS: One hundred and twenty-one patients diagnosed as allergic rhinitis on skin prick tests in group 1 and 100 patients as controls in group 2 had negative skin prick tests. Ninety-one (75.2%) patients had AR on nasal smear eosinophilia in group 1 and 89 (73.6%) patients had AR on serum IgE levels in group 1. Sixty-eight patients (56.2%) were males and 53 (43.8%) were females in group 1. In group 2, 51 (51%) were males and 49 (49%) were females. Mean difference in nasal smear eosinophil count and serum IgE levels in AR and control group was statistically significant (p<0.001). Sensitivity, specificity, PPV and NPV of nasal smear eosinophilia was 77.8%,71.2%, 75.2%, and 74%; and of IgE level was 82.4%, 71.7%, 73.6%, and 81%, respectively. CONCLUSION: Serum IgE and nasal smear eosinophilia levels are helpful in diagnosing allergic rhinitis; however, serum IgE level has better sensitivity and higher NPV than smear eosinophilia. Specificity of both tests is comparable. Key Words: Allergic rhinitis, Nasal smear eosinophilia, Serum IgE level.
