An outbreak of trematode-induced granulomas of the conjunctiva

Purpose: To describe the epidemiologic, clinical, and histopathologic featu res of trematode granulomas of the conjunctiva, eyelid, and anterior chambe r in pediatric patients. Design: Prospective noncomparative case series. Participants: Forty-one children from a southern Indian village with conjun ctival granulomas. Methods: The village of Sellananthal was selected for a field visit after a nalysis of earlier hospital-based allergic conjunctival granuloma cases. Ch ildren with ocular diseases were examined, and histories of exposure to ass umed risk factors and clinical findings were evaluated. Selected patients w ere brought to the base hospital for excisional biopsy. Serial sections obt ained from the excised nodules were examined for the presence of a parasite . Main Outcome Measures: Histopathologic examination of excised conjunctival lesions or response of lesions to local medical therapy. Results: In this year-long prospective study, 41 children (16 years or youn ger; 38 boys and 3 girls) with clinical features of allergic conjunctival g ranulomas were examined. Thirty-four patients were from a single village lo cated in the southern Indian state of Tamil Nadu; the remaining 7 were from various parts of the same state. All children swam in their village's fres hwater pond. Twenty patients with nodules less than 5 mm in diameter receiv ed medical treatment; 13 with larger nodules underwent surgical excision of the lesions, Nine of these 13 cases revealed a zonal granulomatous inflamm ation admired with eosinophilic leukocytes; 4 of these 9 displayed fragment s of the tegument and internal structures of a trematode and Splendore-Hoep pli phenomenon. The remaining 4 of the 13 cases revealed nongranulomatous i nflammation made up of lymphocytes, histiocytes, and eosinophils. Eight pat ients refused surgical treatment. Conclusions: In southern India, one cause of allergic conjunctival granulom as in children seems to be trematode infection. The clustering of cases in a single village and exposure to a village freshwater pond indicate the nee d for an epidemiologic investigation and study of the parasite's life cycle . Sporadic cases from other parts of the state with similar histories of ex posure to their local pond or river water suggest a widespread distribution of the etiologic agent. Ophthalmology 2001;108:1223-1229 (C) 2001 by the A merican Academy of Ophthalmology.