Importance of limbal examination in ocular allergic disease

We present three adult patients having classic symptoms of ocular allergy with findings confined to the limbus in all eyes. Findings in the cornea and the rest of the bulbar and tarsal conjunctivae were within normal limits. Case 1 had numerous limbal follicles; Case 2 had limbal chemosis 360 degrees; and Case 3 had superior perilimbal conjunctival injection, chemosis, and micropannus formation. Limbal scrapings from all patients revealed abundant eosinophils. There was marked clinical improvement after topical cromolyn sodium 4% treatment. Since the limbus was the only structure involved, the diagnosis of "allergic limbitis" was made. We feel that the limbus is an overlooked structure during ocular examination. As in our three cases, the limbus may be the only area involved in ocular allergy. A careful examination of the limbus may provide important clues for the diagnosis of many ocular inflammatory conditions.