Cercarial dermatitis in Adult
There is a worldwide distribution, with human schistosomes more common in tropical climates (most commonly Schistosoma mansoni and Schistosoma hematobium).
Swimmer's itch typically presents as a pruritic rash on skin 24 hours after exposure to water containing cercaria in endemic areas. The cercariae enter the stratum corneum and die within hours. The rash is associated with moderate pruritus that is self-limiting but may persist for several weeks. Some patients may develop a delayed rash several days after initial exposure.
Cercarial dermatitis may become more severe with repeated exposure. Patients may develop edema, papulovesicles, and intense pruritus.
Rare presentations have been reported on the upper extremities after cleaning fish tanks.
There are no age or sex predilections.
B65.3 – Cercarial dermatitis
187115002 – Cutaneous schistosomiasis
Differential Diagnosis & Pitfalls
- Pseudomonas folliculitis (hot tub folliculitis) also occurs beneath the bathing suit.
- Seabather's eruption
- Seaweed dermatitis is more severe and leads to blistering and desquamation; it is also endemic to Hawaii, where seabather's eruption has not been reported.
- "Dogger Bank itch" (Bryozoa dermatitis) is an algae-induced seaweed dermatitis. This condition is found in dockworkers along the North Sea and the Mediterranean. The lesions are chronic and can be disabling.
- Other ocean-dwelling organisms (hydromedusae, crab larvae)
- Scabies / scabies (pediatric)
- Allergic contact dermatitis / contact dermatitis (pediatric) / poison ivy, oak
- Insect bites
- Acute schistosomiasis – Heavy exposure to human schistosomes may result in acute schistosomiasis, which may be associated with urticarial rash, pruritus, limb edema, lymphadenopathy, fever, nausea, and diarrhea.
- Exposure to larvae of crustaceans or remnants of jellyfish tentacles
- Irritant contact dermatitis