Ophthalmia nodosa secondary to intraocular, white-marked tussock caterpillar setae (Orgyia leucostigma) in a 15-year-old

A 15-year-old female presented to the emergency department with a 1-day history of pain and swelling of her right eye following ocular contact with a caterpillar. Caterpillars of the white-marked tussock moth and other related species possess hairlike structures called setae, with angled barbs along their length, allowing them to travel linearly upon penetration of an enemy, resisting backward movement and becoming very difficult to extract once imbedded. When these fine, pointed hairs contact the surface of the eye, they can easily migrate in, eliciting movement of the globe, blinking, and rubbing of the eye in an attempt to remove the offending agent, potentially leading to ophthalmia nodosa. One of the most important aspects of ophthalmia nodosa diagnosis is a thorough history and prompt slit-lamp examination to identify the presence of foreign bodies and where they are located; this will help guide clinical management decisions. This case demonstrates that, depending on the number and location, more than one attempt may be required to remove all of the barbed setae. If ophthalmia nodosa is suspected, it is important to promptly refer to ophthalmology for a thorough eye exam, keep the eye clean, prescribe prophylactic topical antibiotics and/or steroids to reduce the potential for infection and inflammation, and emphasize the importance of keeping the eye protected during the healing process with an eye shield.