Cutaneous Larva Migrans and Larva Currens

Ancylostoma braziliense is most common cause in central and southeastern United States. Other penetrating nematode larvae: A. caninum, Uncinaria stenocephala (hookworm of European dogs), Bunostomum phlebotomum (hookworm of cattle).

Ova of hookworms are deposited in sand and soil in warm, shady areas, hatching into larvae that penetrate human skin. Activities and occupations that pose risk include contact with sand/soil contaminated with animal feces: playing in sandbox, walking barefoot or sitting on beach, working in crawl spaces under houses, gardeners and plumbers, farmers, electricians, carpenters, pest exterminators.

Larva Currens

Filariform larvae of Strongyloides stercoralis can penetrate skin (usually on buttocks), producing similar lesions, i.e., larva currens

Humans are aberrant, dead-end hosts who acquire the parasite from environment contaminated with animal feces. Larvae remain viable in soil/sand for several weeks. Third-stage larvae penetrate human skin and migrate up to several centimeters a day, usually between stratum germinativum and stratum corneum. Parasite induces localized eosinophilic inflammatory reaction. Most larvae are unable to develop further or invade deeper tissues and die after days or months. Migration to viscera causes Loeffler's síndrome

Larva Currens

Caused by S. stercoralis. Papules, urticaria, papulovesicles at the site of larval penetration (Fig. 26-25). Associated with intense pruritus. Occurs on skin around anus, buttocks, thighs, back, shoulders, abdomen. Pruritus and eruption disappear when larvae enter blood vessels and migrate to intestinal mucosa

Treatment: Thiabendazole, orally 50 mg/kg per day in two doses (maximum 3 g/d) for 2 to 5 days; also effective when applied topically under occlusion. Ivermectin, 6 mg bid. Albendazole, 400 mg/d for 3 days; highly effective

Source - Fitzpatrick dermatology