#Swimmers itch bites manual
#Swimmers itch bites skin

The cercariae penetrate the wet skin of warm-blooded animals. Snails infected with schistosome (blood fluke) species shed the infective cercariae into the water. EtiologyĬercarial dermatitis is caused by penetration of the skin by avian or rodent schistosomal larval forms called cercariae.

#Swimmers itch bites manual

Klaus, in The Travel and Tropical Medicine Manual (Fourth Edition), 2008 CERCARIAL DERMATITISĬercarial dermatitis, also known as swimmer's itch, is a self-limited, common parasitic infection in which humans are an incidental host. Differential diagnosis includes insect bites, contact dermatitis, and scabies. Diagnosisĭiagnosis rests on the history of exposure to contaminated water and typical clinical findings. Cercarial dermatitis usually spares areas covered by clothing, in contrast to seabather's eruption (discussed later in this chapter). Subsequent attacks tend to become more severe.

Secondary bacterial infection can occur in excoriated lesions. These lesions reach maximal intensity 2-3 days after infection and then subside within 1-2 weeks. Recurrent infections result in increased inflammatory response. Hours later, pruritic macules, papules, or vesicles may develop in the same sites. Penetration of cercariae is accompanied by a prickling sensation and urticarial wheals, which resolve. There are two phases to cercarial dermatitis: transient symptoms soon after exposure and delayed symptoms. People are exposed by swimming or wading in contaminated water. EpidemiologyĬercarial dermatitis occurs worldwide where either fresh or saltwater is heavily contaminated with infected avian feces. In contrast, pathogenic species of schistosomes can enter the vascular system, where maturing flukes cause systemic disease (see Chapter 48). The cercariae can penetrate the upper layers of human skin but are unable to enter the vascular system, and soon die. The cercariae penetrate the wet skin of warm-blooded animals, including people. EtiologyĬercarial dermatitis is caused by penetration of the skin by avian schistosomal larval forms called cercariae. The number of outbreaks reported is increasing worldwide. Oral antihistamines and topical steroids reduce the symptoms.Įllen Thompson, Andrea Kalus, in The Travel and Tropical Medicine Manual (Fifth Edition), 2017 Cercarial DermatitisĬercarial dermatitis, also known as swimmer's itch, is a self-limited, common parasitic infection in which humans are dead-end hosts. The differential diagnosis includes sea-bather's eruption, contact dermatitis (secondary to marine plants, hydroids, and corals), and insect bites. The diagnosis is made by history of exposure and the characteristic clinical findings. In cases of previous contact, the clinical findings may begin sooner with increased severity and a prolonged course. The eruption peaks in 1–3 days and lasts 1–3 weeks. The eruption typically covers skin surfaces that are exposed to water, but the skin surfaces that are covered by swimwear are not spared. Typically, and approximately 1 hour later, the cutaneous lesions begin as a pruritic macular erythematous eruption that progresses to a papular, papulovesicular, and urticarial eruption. 35 A prickling sensation during or shortly after exposure to infested water may be reported. The time from exposure to onset of symptoms varies from a few minutes to a maximum of 24 hours after exposure. There are sporadic reports and few outbreaks reported from all continents. Cercarial dermatitis occurs in swimmers and those with occupations that include water exposure. The cercariae penetrate intact human skin within a few minutes.

35 Cercarial dermatitis is acquired by skin exposure to fresh and, to a lesser extent, salt water. Eric Caumes, in Travel Medicine (Fourth Edition), 2019 Cercarial DermatitisĬercarial dermatitis (also called clam-digger's dermatitis, schistosome dermatitis, sedge pool itch, swimmer's itch) is caused by the infestation of the skin by cercariae (larvae) of nonhuman schistosomes whose usual hosts are birds and small mammals.