On October 28, 1991, an employee of the Division of Public Health (DPH), Delaware Department of Health and Social Services, reported that her son and at least 10 other persons who had recently participated in a high school biology class field trip to Cape Henlopen State Park had contracted pruritic dermatitis. The Delaware Health Monitoring and Program Consultation Section conducted an investigation to confirm the reported presumptive diagnosis of cercarial dermatitis and to assess the extent of this outbreak.
On October 19, 1991, 37 students aged 13-16 years (median: 14.6 years) and their teacher spent 1.2-6.0 hours (median: 2.8 hours) wading at low tide in a shellfishing area. The weather was sunny and unseasonably warm; the air temperature was 80°F (27°C), the highest recorded in October 1991. During October 20-28, 29 students developed pruritic dermatitis; 11 visited their physicians for treatment.
On November 7, all of the students and their teacher were
Epidemiologic Notes and Reports Cercarial Dermatitis Outbreak at a State Park—Delaware, 1991. Arch Dermatol. 1992;128(6):745–746. doi:10.1001/archderm.1992.01680160025002