Dermatology grand rounds at the NIHRapid development of migratory, linear, and serpiginous lesions in association with immunosuppression

Key teaching points•Strongyloides is a genus of obligate gastrointestinal nematodes (roundworms) of vertebrates. The species stercoralis, the usual cause of human infection, has the potential for autoinfection and multiplication in human beings.•Peripheral eosinophilia without a known cause may represent chronic, persistent infection with Strongyloides stercoralis.•Undiagnosed disease is prevalent, especially among immigrants and military veterans who served in highly endemic areas in the tropics and subtropics.•Immunosuppression of individuals with persistent Strongyloides stercoralis infection can lead to hyperinfection syndrome or disseminated infection, which can be fatal in up to 90% of cases.•First-line therapy for acute and chronic strongyloidiasis is ivermectin, 200 μg/kg orally in a single daily dose for 1 to 2 days. Treatment of hyperinfection syndrome includes reduction of immunosuppression, if possible, and administration of ivermectin (200 μg/kg daily) until larvae are no longer detected in stool for at least 2 weeks.3,17 The spectrum of clinical disease is wide, however, and shorter courses of ivermectin may be sufficient.•Larva currens is a hypersensitivity reaction that refers to the cutaneous manifestation of Strongyloides and should be distinguished from cutaneous larva migrans, which is caused by abortive human infection with an animal hookworm.