Conjunctival Provocation Test in Daily Practice: Four Ocular Symptoms Vs Ocular Pruritus Score System

Conjunctival provocation test (CPT), the confirming diagnostic test of ocular allergy, is underused by clinicians. We compared the diagnostic accuracy of CPT in daily practice using two different symptomś score systems recommended by the EAACI Interest Group on Ocular Allergy: ocular pruritus score (OPS) and 4 total ocular symptoms score (4TOSS). Mixed grass pollen extract (LETI SL, Madrid, Spain) was used for CPT in 11 asymptomatic patients with persistent moderate-severe rhinoconjunctivitis due to grass pollen and 8 controls (4 healthy subjects, and 4 patients with D. pteronyssinus allergic rhinitis). The positive CPT criterion was 4TOSS ≥ 5, or OPS ≥ 2. Response to CPT evaluated by 4TOSS (pruritus, hyperemia, tearing, and chemosis) and OPS were compared with SPT results, the gold standard (SPT). The appearance of nasal and/or bronchial symptoms was also evaluated. OPS had 100% sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and concordance with SPT (kappa index 1, p<0.001). 4TOSS had a high sensitivity (90.9%), specificity (100%), PPV (100%), NPV (88.9%) and concordance with SPT (kappa index 0.894, p<0.001). Thirty six per cent of cases with a positive CPT had a positive nasal response (4 total nasal symptoms score >5). No bronchial symptoms were detected. A significant negative correlation between serum Phleum-sIgE levels and grass pollen threshold CPT concentration was detected (Rho -0.918, p>0.001). The results demonstrated that OPS system is a very useful parameter to assess the response to CPT in patients with moderate-severe allergic rhinoconjunctivitis in daily practise.