Clustered cases of ringworm at an elementary school in Fécamp (76) were reported to health authorities in January 2010. An investigation was conducted by the Interregional Epidemiology Unit, the Regional Health Agency, and the Ministry of Education to determine the cause of the outbreak. The report was confirmed by the microbiology laboratories in Fécamp. A Microsporum-type ringworm transmitted from person to person was identified in the patients. Information about ringworm and its management was distributed to school staff, parents, and the children’s primary care physicians. The goal was to raise awareness about treatment protocols and the implementation of hygiene measures around cases. A weekly active case-finding effort was implemented at the school, conducted by school nurses, to identify the emergence of new cases. Suspected cases were advised to consult their primary care physician to confirm or rule out the diagnosis. Active case finding lasted 15 weeks, up to two months after the last case appeared (the maximum incubation period for the disease). Thirteen children developed dermatophytosis between December 2009 and May 2010, representing 7.5% of the school’s students. Treatment was initiated for all cases, lasting an average of six weeks. No new cases emerged after treatment began. The key factors in resolving the outbreak were: rapid mobilization of health services and strong involvement of the school health program in monitoring the outbreak; raising awareness among the students’ primary care physicians regarding optimal case management protocols; and providing updated information to parents and teachers to ensure proper adherence to treatment regimens. (R.A.)