Conjunctival eosinophilia in atopic and non-atopic external eye symptoms

We studied the occurrence in an ophthalmological office practice of conjunctival eosinophilia in 333 normal subjects (mean age 26 years) and in 152 atopic and 484 non-atopic patients (mean age 40 years) with various external eye symptoms. Eosinophils were present in 131/636 patients (21%) and in 22/333 asymptomatic normal subjects (7%). In those patients with conjunctival eosinophilia, a history of some kind of atopic condition was obtained only in 53/131 (40%). When the patients were characterized according to the presence of both eosinophilia and atopy, eosinophilia without signs of atopy was observed in 7-15% in different diagnostic groups. Patients with conjunctivitis or blepharoconjunctivitis had a fourfold risk for eosinophilia compared to normal subjects (odds ratios 4.52 and 4.09, confidence intervals 2.02, 10.12 and 2.40, 6.99), when atopy, sex, age, time of the examination and presence of bacteria were included as potential confounders in the regression model. We conclude that a considerable portion of patients with external eye symptoms, and especially with various forms of conjunctivitis, show eosinophilic inflammation without any evidence of atopic background. They can be labelled as having 'intrinsic' eosinophilic conjunctivitis analogously to the classification used in patients with intrinsic rhinitis and asthma. The etiology of this common nonatopic syndrome remains to be established.