eMedicine Specialties > Dermatology > Parasitic Infections

Cutaneous Larva Migrans

Author: Lydia A Juzych, MD, Consulting Staff, Department of Dermatology, Henry Ford Health Sciences Center
Coauthor(s): Margaret C Douglass, MD, Program Director, Department of Dermatology, Henry Ford Hospital
Contributor Information and Disclosures

Updated: Nov 20, 2009

Introduction

Background

Cutaneous larva migrans (CLM) is the most common tropically acquired dermatosis whose earliest description dates back more than 100 years. Cutaneous larva migrans manifests as an erythematous, serpiginous, pruritic, cutaneous eruption caused by accidental percutaneous penetration and subsequent migration of larvae of various nematode parasites. Cutaneous larva migrans is most commonly found in tropical and subtropical geographic areas and the southwestern United States; however, the ease and the increasing incidence of foreign travel by the world's population have no longer confined cutaneous larva migrans to these areas.^1,2,3,4,5

Also see the eMedicine Pediatrics articles Ancylostoma Infection and Cutaneous Larva Migrans.

Pathophysiology

In cutaneous larva migrans (CLM), the life cycle of the parasites begins when eggs are passed from animal feces into warm, moist, sandy soil, where the larvae hatch. They initially feed on soil bacteria and molt twice before the infective third stage. By using their proteases, larvae penetrate through follicles, fissures, or intact skin of the new host. After penetrating the stratum corneum, the larvae shed their natural cuticle. Usually, they begin migration within a few days.

In their natural animal hosts, the larvae of cutaneous larva migrans are able to penetrate into the dermis and are transported via the lymphatic and venous systems to the lungs. They break through into the alveoli and migrate to the trachea, where they are swallowed. In the intestine they mature sexually, and the cycle begins again as their eggs are excreted.

Humans are accidental hosts, and the larvae are believed to lack the collagenase enzymes required to penetrate the basement membrane to invade the dermis. Therefore, cutaneous larva migrans remains limited to the skin when humans are infected.

Frequency

United States

Cutaneous larva migrans is rated second to pinworm among helminth infections in developed countries.

Mortality/Morbidity

Cutaneous larva migrans is benign and self-limited but can cause a disturbing pruritus.

Race

No specific racial predilection exists because cutaneous larva migrans depends on exposure.

Sex

Cutaneous larva migrans demonstrates no specific sexual predilection because cutaneous larva migrans depends on exposure.

Age

Cutaneous larva migrans can affect persons of all ages because it depends on exposure, but it tends to be seen in children more commonly than in adults.

Clinical

History

• Tingling/prickling at the site of exposure within 30 minutes of penetration of larvae, although Archer describes a case of late-onset cutaneous larva migrans (CLM)⁶
• Intense pruritus
• Erythematous, often linear lesions that advance
• Often associated with a history of sunbathing, walking barefoot on the beach, or similar activity in a tropical location
• Predispositions to contracting cutaneous larva migrans include the following:
  • Hobbies and occupations that involve contact with warm, moist, sandy soil
  • Tropical/subtropical climate travel
  • Barefoot beachgoers/sunbathers
  • Children in sandboxes
  • Carpenter
  • Electrician
  • Plumber
  • Farmer
  • Gardener
  • Pest exterminator

Physical

• Cutaneous signs of cutaneous larva migrans (CLM) include the following:
  • Pruritic, erythematous, edematous papules and/or vesicles
  • Serpiginous (snakelike), slightly elevated, erythematous tunnels that are 2- to 3-mm wide and track 3-4 cm from the penetration site (see Media Files 1-3)
  • Nonspecific dermatitis
  • Vesicles with serous fluid
  • Secondary impetiginization
  • Tract advancement of 1-2 cm/d
• Systemic signs include peripheral eosinophilia (Loeffler syndrome), migratory pulmonary infiltrates, and increased immunoglobulin E (IgE) levels, but are rarely seen.
• Lesions are typically distributed on the distal lower extremities, including the dorsa of the feet and the interdigital spaces of the toes, but can also occur in the anogenital region, the buttocks, the hands, and the knees.

Causes

• Common etiologies and where the parasites of cutaneous larva migrans (CLM) are most commonly found include the following:
  • Ancylostoma braziliense (hookworm of wild and domestic dogs and cats) is the most common cause. It can be found in the central and southern United States, Central America, South America, and the Caribbean.
  • Ancylostoma caninum (dog hookworm) is found in Australia.
  • Uncinaria stenocephala (dog hookworm) is found in Europe.
  • Bunostomum phlebotomum (cattle hookworm)
• Rare etiologies include the following:
  • Ancylostoma ceylonicum
  • Ancylostoma tubaeforme (cat hookworm)
  • Necator americanus (human hookworm)
  • Strongyloides papillosus (parasite of sheep, goats, and cattle)
  • Strongyloides westeri (parasite of horses)
  • Ancylostoma duodenale
  • Pelodera (Rhabditis) strongyloides⁷

• Search for CME/CE on This Topic »

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