Pruritic Skin Eruption on the Left Foot of a 36-Year-Old Woman

Figure 1. Cutaneous larva migrans on the left foot of a 36-year-old woman Diagnosis: Cutaneous larva migrans. Cutaneous larva migrans, also known as " creeping eruption, " is caused by larvae of the cat and dog hookworm. It is characterized by serpiginous, reddened, elevated, pruritic skin le-sions usually caused by Ancylostoma braziliense [1]. It occurs in warmer climates and is one of the most common dermatoses among travelers returning from tropical countries [2]. In the United States, most cases are found in the southeastern and central regions [2, 3]. Dogs or cats that carry the hookworms deposit the larvae, which are present in their feces, into the sand or soil, where the larvae can survive for several days. On contact with unprotected skin, the larvae penetrate the epidermis but are contained by the basement membrane. Humans are incidental hosts, and the hookworms cannot complete their life cycle in humans. The infection causes erythematous, pruritic papules. In 5–14 days, the characteristic reddened, intensely pruritic skin eruption is visible along the path of larval migration (figure 1) [2]. Cutaneous larva migrans is usually self-limited, with most cases lasting a few weeks or months. The diagnosis is based on clinical appearance and a history of probable exposure. Eosinophilia is not common but has been noted in some cases of infection. In one series, up to 20% of patients had eosinophilia [4]. Biopsy is not indicated because the migrating parasite is usually not identified. Treatment is not required, but it is usually recommended to manage intense cases of pruritus. Topical (2–3 times per day for 5 days) and oral (25 mg/kg 2 times per day for 2 days) thiabendazole are effective. Successful treatment with albendazole or ivermectin has also been reported [1]. Our patient was initially treated with thiabendazole, but her symptoms persisted. She was then treated with ivermectin for