Cutaneous larva migrans
2219 is a skin disease caused by the larvae of various nematode parasites of the hookworm family.
The most common species causing this disease in the Americas is Ancylostoma braziliense.
Accounts for more than 8% of acquired skin conditions among tourists traveling to endemic areas which include: tropical and warm regions within Latin America, the Caribbean, Southeast Asia, and sub-Saharan Africa.
It is the most common dermatological disease presenting in patients after their travel to the Caribbean.
Adult hookworms commonly reside in the intestines of dogs, cats, wild animals and shed their eggs the animal feces.
Humans are incidental hosts and the larvae are only able to penetrate the epidermis of the skin.
Moist and warm environments are favorable conditions and include beaches and soil, for which egg hatching and survival of the larvae are enabled.
Larvae hatch within 1-2 days and mature into an effective third stage filariform larvae within one week.
Transmission of the infection occurs on direct contact of human skin with contaminated soil or sand, and the larvate can penetrate into the epidermis.
The larvae lacks lytic collagenase enzymes necessary to cross the epidermal basement membrane to invade the dermis and is the reason why larvae maybe found confined to the hair follicle.
Because larvae are limited to the epidermis, the infection is usually self-limiting with resolution within 2-8 weeks, but can persist up to a year.
CLM presents with itching soon after larval penetration into the epidermis.
If the rash is scratched severely, it may allow a secondary bacterial infection to develop.
The earliest clinical sign is a small erythematous papule at the site of injury.
Following epidermis penetration the larvae can migrate, and create serpiginous erythematous, elevated linear tracks known as the “creeping eruption“.
Most individuals have a single linear track although multiple tracks have been reported.
Linear lesions usually measure 2-4 mm in width, and become visible 1-5 days following penetration.
Incubation period of a month or longer have been reported.
The linear tracks are most commonly found on the abdomen, feet, buttocks, hands, or genitals, but can be located anywhere on the body’s surface.
Larvae can migrate up to a few centimeters a day.
Vesicobullous lesions result from accumulation of serous fluid occurs in 9-15% of cases.
Sleep disturbances is reported in 84% of patients, probably due to pruritis.
CLM is self limited, but anti-helminth treatment including albendazole and Ivermectin can shorten disease duration.
Following proper treatment, migration of the larvae within the skin is halted and relief of the associated itching can occur in less than 48 hours.
Thiabendazole agent which can be applied either topically or taken by mouth is thiabendazole is an anti-helminthic that is effective treatment.
Topical steroids are recommended to decrease scratching.
Prevention:
Wearing shoes in areas where these parasites are known to be endemic.
Avoiding exposure of skin to contaminated soil or sand offers the best protection.
Diagnosis is predominately based on clinical presentation and history, although biopsies may be performed to find parasites in biopsy sections.
Biopsies however are usually negative to identify hook worm larvae.