cutaneous larva migrans

Introduction

A migratory, serpinginous or netlike tunneling in the skin.

Etiology

• Ancylostoma braziliense: dog & cat feces
• Ancylostoma canium
• Ancylostoma duodenale
• Uncinaria stenocephala (European dog hookworm)
• Bunostomum phlebotomum (cattle hookworm)
• Strongyloides

Epidemiology

• eastern & southern coastal USA
• other tropical or subtropical coastal areas
• transmission occurs when naked skin comes into contact with contaminated soil

Pathology

• wandering hookworm larvae not adapted to intestinal maturation in humans
• entry is generally through the skin
• cutaneous larva migrans (migration of hookworm larvae in the epidermis)
• larvae cannot penetrate the basal membrane of human skin, because it lacks the collagenase necessary to break through the basement membrane, thus remain confined to the epidermis & are unable to develop & complete their lifecycle
• self-limiting disease
• skin pathology may persist for months

Clinical manifestations

• first clinical sign is a small reddish papule
• later, the characteristic serpiginous, slightly elevated, erythematous track becomes visible
• migration occurs at a rate of a few mm to cm per day
• pruritus becomes more & more intense
• excoriations induced by scratching

*images

Laboratory

• skin biopsy generally not needed (diagnosis is clinical)

Complications

• bacterial superinfection from scratching

Management

• self-limited disease; however, anthelmintic treatment can diminish symptoms & shorten the duration
• with treatment, lesions may heal completely in 2 weeks
• drug of choice is ivermectin in a single dose (200 ug/kg)
• albendazole 400 mg QD is alternative

More general terms

• larva migrans