Case report: Ocular gnathostomiasis in northwestern Mexico.

A 42-year-old woman from Culiacan in the Sinaloa State of Mexico presented with a four-year history of migratory, pruritic, painful swellings of the face. Palpebral edema with conjunctival erythema developed when lesions developed near the eye. Routine eye examination showed a mobile worm in the anterior chamber. Following surgical removal, the parasite was identified by light and electron microscopy as an advanced third-stage larva of Gnathostoma sp. This prevalence of this helminthiasis may be increasing in areas where eating freshwater raw fish ("cebiche") is customary.