Parasitic Infections of the Skin and Subcutaneous Tissues

Abstract

A variety of arthropods, protozoa, and helminths infect the skin and subcutaneous tissues and may be identified by anatomic pathologists in standard cytology and histology preparations. The specific organisms seen vary greatly with the patient's exposure history, including travel to or residence in endemic countries. Arthropods are the most commonly encountered parasites in the skin and subcutaneous tissues and include Sarcoptes scabei, Demodex species, Tunga penetrans, and myiasis-causing fly larvae. Protozoal parasites such as Leishmania may also be common in some settings. Helminths are less often seen, and include round worms (eg, Dirofilaria spp.), tapeworms (eg, Taenia solium, Spirometra spp.), and flukes (eg, Schistosoma spp.). This review covers the epidemiologic and histopathologic features of common parasitic infections of the skin and subcutaneous tissues.

Pruritic Cutaneous Nematodiasis Caused by Avian Eyeworm Oxyspirura Larvae, Vietnam

“…Although rare, larvae of the free-living nematode Pelodera strongyloides can infect humans and cause multiple pruritic skin lesions (13). Regardless of various clinical features, nematode larvae in humans usually cause focal skin lesions in limited areas (2). The case we report is an unusual example of disseminated pruritic lesions caused by Oxyspirura larvae.…”

“…Gnathostoma spp. larvae can cause either creeping eruption or migratory panniculitis (2,10). In Japan, Spirurina type X larvae in scintillant squids, now identified as the larvae of Crassicauda giliakiana, cause cutaneous creeping eruptions (11).…”

“…V arious nematode parasites are known to cause cutaneous lesions in humans. Some species, such as nonlymphatic filaria Onchocerca vorvuls and Loa loa, exploit skin tissues to become mature adults and reproduce (1,2). Other species, usually animal hookworms such as Ancylostoma braziliense and A. caninum, as well as other less common species (2,3), remain larval or immature and accidentally migrate into cutaneous tissues (1).…”

“…Some species, such as nonlymphatic filaria Onchocerca vorvuls and Loa loa, exploit skin tissues to become mature adults and reproduce (1,2). Other species, usually animal hookworms such as Ancylostoma braziliense and A. caninum, as well as other less common species (2,3), remain larval or immature and accidentally migrate into cutaneous tissues (1). Clinical manifestations of cutaneous parasitic infections include migratory nodular lesions or erythema when parasites are in the deeper part of subcutis and serpiginous creeping eruptions when worms migrate through or just under the epidermis.…”

“…Clinical manifestations of cutaneous parasitic infections include migratory nodular lesions or erythema when parasites are in the deeper part of subcutis and serpiginous creeping eruptions when worms migrate through or just under the epidermis. Regardless of clinical manifestation, skin lesions caused by nematode parasites tend to be focal, except when larva currens of Strongyloides stercoralis (2,4) are involved and cause disseminated strongyloidiasis. We describe a case of disseminated cutaneous nematodiasis caused by Oxyspirura larvae, adult nematodes of which are known as avian eyeworms.…”