Cutaneous larva migrans (abbreviated CLM) is a skin disease in humans, caused by the larvae of various nematode parasites of the

hookworm Hookworms are intestinal, blood-feeding, parasitic roundworms that cause types of infection known as helminthiases. Hookworm infection is found in many parts of the world, and is common in areas with poor access to adequate water, sanitation, an ...

family (

Ancylostomatidae The Ancylostomatidae are a family of worms that includes the hookworms. Genera of Ancylostomatidae * '' Agriostomum'' * ''Ancylostoma'' * ''Bunostomum ''Bunostomum'' is a genus of nematodes of the small intestine of ruminants and camelids. ...

). These parasites live in the intestines of dogs, cats, and wild animals and should not be confused with other members of the hookworm family for which humans are definitive

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County People *Jim Host (born 1937), American businessman * Michel Host ...

s, namely ''

Ancylostoma duodenale ''Ancylostoma'' is a genus of nematodes that includes some species of hookworms. Species include: : '' Ancylostoma braziliense'', commonly infects cats, popularly known in Brazil as ''bicho-geográfico'' : '' Ancylostoma caninum'', commonly infe ...

'' and '' Necator americanus''. Colloquially called creeping eruption due to its presentation, the disease is also somewhat ambiguously known as "

ground itch Ground itch refers to the inflammatory reaction resulting from certain helminthic invasions into the skin. Presentation Effects due to Penetration by larvae * Maculopapular rash * Localized erythema * Intense itching ( usually between the toes ) ...

" or (in some parts of the southern United States) "sandworms", as the larvae like to live in sandy soil. Another vernacular name is plumber's itch. The medical term CLM literally means "wandering larvae in the skin".

Symptoms and signs

The infection causes a red, intensely pruritic (itchy) eruption, and may look like twirling lesions. The itching can become very painful and if scratched may allow a secondary bacterial infection to develop. Cutaneous larva migrans usually heals spontaneously over weeks to months and has been known to last as long as one year. However, the severity of the symptoms usually causes those infected to seek medical treatment before spontaneous resolution occurs. 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 (reported for thiabendazole). This is separate from the similar cutaneous

larva currens Larva currens (Latin for racing larva) is an itchy, cutaneous condition caused by infections with ''Strongyloides stercoralis.'' It is caused by the intradermal migration of strongyloides and distinguished from cutaneous larva migrans (caused by ho ...

which is caused by ''

Strongyloides ''Strongyloides'' (from Greek ''strongylos'', round, + ''eidos'', resemblance), anguillula, or threadworm is a genus of small nematode parasites, belonging to the family Strongylidae, commonly found in the small intestine of mammals (particularl ...

''. Larva currens is also a cause of migratory pruritic eruptions but is marked by 1) migratory speed on the order of inches per hour 2) perianal involvement due to autoinfection from stool and 3) a wide band of urticaria.

Cause

Hookworm eggs are shed in the infected dog (or other animal) feces to the ground and beach sand, where they then develop over a period of 1–2 weeks into the infectious larval form (filariform larvae). The filariform larvae can burrow through intact skin that comes into contact with soil or sand that is contaminated with feces. Although they are able to infect the deeper tissues of animals (through to the lungs and then the intestinal tract), humans are incidental

s and the larvae are only able to penetrate the epidermis of the skin and thus create the typical wormlike burrows visible underneath the skin. These parasites apparently lack the collagenase enzymes required to penetrate through the

basement membrane The basement membrane is a thin, pliable sheet-like type of extracellular matrix that provides cell and tissue support and acts as a platform for complex signalling. The basement membrane sits between Epithelium, epithelial tissues including mesot ...

deeper into the dermal layers of the skin.

Treatment

CLM can be treated in a number of different ways: * Systemic (oral) agents include albendazole (trade name ''Albenza'') and ivermectin (trade name ''Stromectol''). * Another agent which can be applied either topically ''or'' taken by mouth is thiabendazole (trade name ''Mintezol''), an anti-helminthic. * Topical freezing agents, such as ethylene chloride or

liquid nitrogen Liquid nitrogen—LN2—is nitrogen in a liquid state at low temperature. Liquid nitrogen has a boiling point of about . It is produced industrially by fractional distillation of liquid air. It is a colorless, low viscosity liquid that is wide ...

, applied locally can freeze and kill the larvae, but this method has a high failure rate because the larvae are usually located away from the site of the visible skin trails. Additionally, this is a painful method which can cause blistering and/or ulceration of the skin and it is therefore not recommended. * It is recommended to use Benadryl or some anti-itch cream (i.e. Cortizone or Calamine lotion). This will help relieve some of the itch. * Wearing shoes in areas where these parasites are known to be endemic offers protection from infection. In general, avoiding exposure of skin to contaminated soil or sand offers the best protection. In some areas dogs have been prohibited from beaches in an attempt to control human infection.

Additional images

File:Cutaneous larva migrans 1.jpg File:Cutaneous-larva-migrans-foot.jpg

References

External links