Clinical Images: Cercarial Dermatitis

Kerry Gardner, MD,1 Joseph M. Lam, MD, FRCPC,2

1Resident, Department of Dermatology and Skin Science, University of British Columbia, BC.
2Clinical Assistant Professor, Department of Pediatrics and Dermatology, University of British Columbia, BC.


Abstract: Cercarial dermatitis (swimmers' itch) consists of urticarial papules that form when the larvae of avian parasitic flatworms penetrate the skin. Cercarial dermatitis is common in the summer months where heaviest recreational swimming occurs, and when the temperature is ideal for amplified schistosome development.
Key Words: cercarial dermatitis (swimmers' itch), non-communicable, water-borne disease.
Cercarial dermatitis usually occurs with exposure to fresh water, but can occur with shallow salt water exposure as well.
The eruption typically occurs on uncovered skin 12-24 hours (up to 8 days) after exposure.
The eruption is self-limited, lasting 4-10 days (up to 20 days).
To have access to full article that these tools were developed for, please subscribe. The cost to subscribe is $80 USD per year and you will gain full access to all the premium content on, an educational portal, that hosts 1000s of clinical reviews, case studies, educational visual aids and more as well as within the mobile app.
Disclaimer at the end of each page