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

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

s of the

hookworm Hookworms are Gastrointestinal tract, intestinal, Hematophagy, blood-feeding, parasitic Nematode, 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 ...

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

( Ancylostomatidae). The parasites live in the intestines of dogs, cats, and wild animals; they 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 * Host Island, in the Wilhelm Archipelago, Antarctica People * ...

s, namely '' Ancylostoma duodenale'' and '' Necator americanus''. Colloquially called creeping eruption due to its presentation, the disease is also somewhat ambiguously known as " ground itch" 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. After 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 which is caused by '' Strongyloides''. 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. File:Cutaneous larva migrans 1.jpg File:Cutaneous-larva-migrans-foot.jpg

Cause

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

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different ...

. They create the typical wormlike burrows which are visible underneath the skin. These parasites apparently lack the collagenase

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

s required to penetrate through the

basement membrane The basement membrane, also known as base 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 epithelial tis ...

deeper into the dermal layers of the skin.

Diagnosis

Observing the lesions with the naked eye is sufficient to make a clinical diagnosis. Finding the larvae is difficult due to their small size and identifying the

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

to which they belong is more complicated. Therefore, careful observation of the serpiginous lesions, which progressively increase in length, as well as a history of contact with sandy soil contaminated with dog or cat feces, mainly on beaches, is considered sufficient for a correct diagnosis.

Treatment

CLM can be treated in a number of different ways: * Systemic (oral) agents include

albendazole Albendazole is a broad-spectrum antihelmintic and antiprotozoal agent of the benzimidazole type. It is used for the treatment of a variety of intestinal parasite infections, including ascariasis, pinworm infection, hookworm infection, trichuri ...

(trade name ''Albenza'') and

ivermectin Ivermectin is an antiparasitic drug. After its discovery in 1975, its first uses were in veterinary medicine to prevent and treat heartworm and acariasis. Approved for human use in 1987, it is used to treat infestations including head lice ...

(trade name ''Stromectol''). * Another agent which can be applied either topically ''or'' taken by mouth is

thiabendazole Tiabendazole (International Nonproprietary Name, INN, British Approved Name, BAN), also known as thiabendazole (Australian Approved Name, AAN, United States Adopted Name, USAN) or TBZ and the trade names Mintezol, Tresaderm, and Arbotect, is a pr ...

(trade name ''Mintezol''), an anti-helminthic. * Topical freezing agents including ethylene chloride or

liquid nitrogen Liquid nitrogen (LN2) is nitrogen in a liquid state at cryogenics, low temperature. Liquid nitrogen has a boiling point of about . It is produced industrially by fractional distillation of liquid air. It is a colorless, mobile liquid whose vis ...

, 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 is therefore not recommended. * To relieve some of the itch,

Benadryl Benadryl is a brand of various antihistamine medications used to stop allergy, allergies, whose content varies in different countries, but which includes some combination of diphenhydramine, acrivastine, or cetirizine. It is sold by Kenvue and ...

or anti-itch creams such as

hydrocortisone Hydrocortisone is the name for the hormone cortisol when supplied as a medication. It is a corticosteroid and works as an anti-inflammatory and by immune suppression. Uses include conditions such as adrenocortical insufficiency, adrenogenit ...

calamine Calamine, also known as calamine lotion, is a medication made from powdered calamine (mineral), calamine mineral that is used to treat mild itchiness. Conditions treated include sunburn, insect bites, Toxicodendron radicans, poison ivy, poiso ...

lotion can help. * 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.

References

External links