DESCRIPTION

Infestation of the epidermis by the infectious larvae of certain nematodes, classically manifesting with an intensely pruritic, serpiginous skin lesion; also known as “creeping eruption”

EPIDEMIOLOGY

Worldwide distribution; most frequent in warmer, tropical climates, including the Caribbean, Africa, South America, Southeast Asia, and southeastern United States

ETIOLOGY

• Most common organism is infective larvae of dog or cat hookworm, Ancylostoma braziliense.
• Other species include Ancylostoma caninum, Uncinaria stenocephala, and Bunostomum phlebotomum.

RISK FACTORS

• Contracted from sand or soil contaminated with dog and cat feces
• Occupational exposures occur from crawling under buildings, such as among plumbers and pipefitters.

PATHOPHYSIOLOGY

• Route of spread
  • Primary host (dog or cat) passes eggs to ground through feces.
  • Warm sand/soil acts as an incubator.
  • Eggs mature into rhabditiform larvae (noninfectious), which molt in 5 days to filariform larvae (infectious).
• Humans are accidental hosts.
• Filariform larvae penetrate the epidermis either through hair follicles, skin fissures, or through intact skin with the use of proteases.
• Larvae are unable to penetrate the basement membrane of the dermis; therefore, the infection remains limited to the epidermis.
• Larvae cannot complete their life cycle in the human host and die within weeks to months.
• Symptoms are due to hypersensitivity to the organism or its excreta.