A survey on Sensitivity and Specificity of Serum Total IgE and Nasal Eosinophil Count in Diagnosis of Allergic Rhinitis and the Relationship between the Tests and Clinical Manifestation Severity

Allergic rhinitis, one of the rhinitis syndromes, is associated with a symptom complex characterized by paroxysms of sneezing, rhinorrhea, nasal obstruction, and itching of the eyes, nose, and palate. Allergic rhinitis is associated with significant morbidity. The main goal of this study is to determine the sensitivity and the specificity of both said paraclinic test and the relationship between clinical manifestation severity and paraclinic test results.

This study is a cross-sectional one with forward direction has been performed in allergy clinic of Esfahan Alzahra hospital. The sampling was done in consecutive nonrandom mode. The tool of gathering the data were a questionnaires asking about age, sex, family history, smoking, pet contact, allergic rhinitis type, severity and frequency of clinical presentation; Also total serum IgE, nasal eosinophil count and Prick skin test results noted in questionnaires. The gathered data was analyzed by SPSS(v.17) software.

All of the questionnaires were analyzed. There were significant differences in patients Prick skin test results as the gold standard test depend on their family history and place of life; Also total serum IgE titer and nasal eosinophil count in patient who have positive skin test was significantly more than otherwise who have negative skin test. For the other analyzed factors there were no significant differences in patient Prick skin test result as the gold standard test. There was no significant relation between total serum IgE titer and clinical presentation severity and frequency, a same result was seen about nasal eosinophil count too. Based on Spearman’s correlation coefficient there was no significant correlation between total serum IgE titer and nasal eosinophil count; however this correlation coefficient will be raised ever the clinical presentation severity raises. The calculated cut of point for total serum IgE titer in this study was 61 IU/mL with 75% specificity and 80% sensitivity. The calculated cut of point for nasal eosinophil percentage in this study was 5% with 100% specificity and 72.7% sensitivity.Discuss: Noticing the obtained results, It seems the physicians should concern family history and place of life in history taking as a important clue to allergic rhinitis diagnosis. This study clarified that total serum IgE titer and nasal eosinophil count can be acceptable paraclinic tests to allergic rhinitis diagnosis; but they should not be used to determine or guess how much the disease severity is.