Comparison of conjunctival and nasal provocation tests in allergic rhinitis children with Dermatophagoides pteronyssinus sensitization

Abstract

Background: Nasal provocation tests (NPTs) are indicated in confirming the diagnosis of allergic rhinitis if the clinical history, skin tests or sIgE are inconclusive. NPTs are time- consuming, technically difficult and expensive to perform. Consequently, conjunctival provocation tests (CPTs), which are easier, cheaper and safer should be considered as an alternative method. No recent study has compared CPTs with NPTs in allergic rhinitis children. Objective: To compare CPTs with NPTs in allergic rhinitis children with house dust mite sensitization Methods: Fifty-five children with allergic rhinitis were included. Thirty-six children had positive skin prick tests (SPTs) to Dermatophagoides pteronyssinus (Dp). NPTs were performed by spraying 0.1 ml of Dp extract with concentrations of 50, 200 and 500 AU/ml to each nostril at 15 minute interval. The clinical symptom scores, anterior rhinomanometry results and nasal peak flow testing were performed to assess the responses. For CPTs, 0.1 ml of the same concentration of allergen extract was dropped into one eye and the control solution was dropped into the other. The responses were assessed by clinical symptom scores. The tests were stopped when the subject reported a positive response, or continued to the maximum concentration. Results: The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CPT compared with NPT are 97.1% (84.7-99.9), 90.5% (69.6-98.8), 94.3% (80.8-99.3), 95% (75.1-99.9) and 94.5 (84.9-98.9), respectively in all patients. Among individual allergic rhinitis subjects the sensitivity, specificity, PPV and NPV are 100%. Conclusions: CPT can be an alternative test for NPT in allergic rhinitis children with house dust mite sensitization, even if they do not have conjunctival symptoms.