Cutaneous larva migrans is caused principally by larvae of the dog and cat hookworms, Ancylostoma braziliense and A caninum. Other animal hookworms, gnathostomiasis, and strongyloidiasis may also cause this syndrome. Infections are common in warm areas, including the southeastern United States. They are most common in children. The disease is caused by the migration of worms through skin; the nonhuman parasites cannot complete their life cycles, so only cause cutaneous disease.
Intensely pruritic erythematous papules develop, usually on the feet or hands, followed within a few days by serpiginous tracks marking the course of the parasite, which may travel several millimeters per day (Figure 35–8) (eFigure 35–45). Several tracks may be present. The process may continue for weeks, with lesions becoming vesiculated, encrusted, or secondarily infected. Systemic symptoms and eosinophilia are uncommon.
Close-up of a serpiginous burrow from cutaneous larva migrans on the leg. The actual larva is 2–3 cm beyond the visible tracks. (From John Gonzalez, MD; used, with permission, from Usatine RP, Smith MA, Mayeaux EJ Jr, Chumley, H. The Color Atlas of Family Medicine, 2nd ed. McGraw-Hill, 2013.)
Cutaneous larva migrans on the foot. (Used, with permission, from Richard P. Usatine, MD, in Usatine RP, Smith MA, Mayeaux EJ Jr, Chumley HS. The Color Atlas and Synopsis of Family Medicine, 3rd ed. McGraw-Hill, 2019.)
The diagnosis is based on the characteristic appearance of the lesions. Biopsy is usually not indicated.
Without treatment, the larvae eventually die and are absorbed. Mild cases do not require treatment. Thiabendazole (10% aqueous suspension) can be applied topically three times daily for 5 or more days. Systemic therapy with albendazole (400 mg orally once or twice daily for 3–5 days) or ivermectin (200 mcg/kg orally single dose) is highly effective.
et al. Management of imported cutaneous larva migrans: a case series and mini-review. Travel Med Infect Dis. 2015;13:382.