An outbreak of paederus dermatitis in a suburban hospital in Sri Lanka.

BACKGROUND: In a modern hospital built recently in Sri Lanka the staff members on night shifts and some patients in the open wards were known to be affected by an acute vesicating dermatitis. The study was carried out to identify the cause of the dermatitis and recommend preventive measures. METHODS: Members of the hospital staff and patients who developed an acute vesicating dermatitis over a period of 2 years were studied using a questionnaire. The clinical features, relationship to night shifts and the month of occurrence were noted. Insects were caught at night on several occasions and identified. Lesions were reproduced in volunteers. RESULTS: Out of a total of 124 patients studied, 108 were members of the hospital staff and it was noted that they had all been on night shifts within 2 days prior to the onset of the lesions. The insect caught belongs to class Coleoptera, family Staphylinidae, genus Paederus, and species fuscipes. The incidence was seasonal with clustering of cases seen to occur twice a year. CONCLUSIONS: This is an outbreak of dermatitis due to Paederus fuscipes. Awareness of the condition and its clinical features will prevent misdiagnosis and the simple preventive measures suggested are based on the behavioral pattern of this nocturnal beetle.