Allergic lacrimal obstruction.

Five patients with ocular allergy and intermittent epiphora had a temporary obstruction at the level of the lacrimal sac or canaliculus. The obstruction probably resulted from mucosal edema induced by rubbing the pruritic periocular tissues, a maneuver commonly performed by such patients. Treatment was aimed at inhibiting the allergic response with cromolyn sodium eyedrops, and patients were instructed to refrain from rubbing the periocular tissues.