Creeping Eruption

The foot of a 10-year-old boy demonstrates the unique wandering cutaneous lesions of creeping eruption, or cutaneous larva migrans. This disorder is caused by skin penetration of hookworm larvae. It is seen in the southeastern United States and tropical and subtropical regions throughout the world.

Creeping eruption in the United States is most frequently caused by the hookworm larvae of Ancylostoma braziliense. Adult nematodes thrive and reproduce in the bowels of cats and dogs. The animals shed the ova in their feces; subsequently, larvae develop, contaminate the soil, and infest other animals. These parasites also penetrate human skin where it comes in contact with the contaminated soil (A). However, the human epidermal basement membrane does not allow further penetration, and the trapped larvae randomly creep along the basement membrane (B).

Pruritus usually is noted from 1 to 3 weeks after larvae invasion and the characteristic eruption appears. The larvae remain concealed approximately 1 cm ahead of the leading edge of erythema. Eosinophilia may develop in as many as 30% of patients. If the patient is untreated, the larvae normally die in 2 to 3 weeks, but they may survive for as long as 1 year.

The treatment of choice is a 1-week course of 15% thiabendazole applied three times daily. Instruct your patients to apply this agent so that it extends 2- to 3-cm beyond the visible cutaneous lesions. This treatment is effective in 98% of patients with creeping eruption.