cutaneous larva migrans

Cutaneous Larva Migrans 

Definition

Cutaneous larvae migrans is a parasitic skin disease caused by a hookworm larvae that usually infests dogs, cats, and other animals. Humans can pick up the infection by walking barefoot on soil or beaches contaminated with animal feces.

Description

Cutaneous larvae migrans (also called "creeping eruption" or "ground itch") is found in southeastern and Gulf states, and in tropical developing countries.

The hookworms that cause the condition are small, round blood-sucking worms that infest about 700 million people around the world. Cutaneous larvae migrans occurs most often among children, those who crawl beneath raised buildings, and sunbathers who lie down on wet sand contaminated with hookworm larvae.

Causes and symptoms

After an animal passes feces that are infested with hookworm eggs, the eggs hatch into infective larvae that are able to penetrate human skin (even through solid material, such as a beach towel). The larvae are commonly found in shaded, moist, or sandy areas (such as beaches, a child's sandbox, or areas underneath a house), where they are easily picked up by bare feet or buttocks.

In minor infestations, there may be no symptoms at all. In more severe cases, a red elevation of the skin (papule) appears within a few hours after the larvae have penetrated the skin. This usually arises first in areas that are in contact with the soil, such as the feet, hands, and buttocks.

Between a few days and a few months after infection, the larvae begin to migrate beneath the skin, leaving extremely itchy red lines that may be accompanied by blisters. These red lines usually appear at the top of the sole of the foot or on the buttocks.

Tyically, the larvae travel through the bloodstream, to the lungs, and then migrate into the mouth where they are swallowed and attach to the small intestine lining. There they mature into adult worms. In cases where the larvae migrate through the lungs, they can produce anemia, cough, and pneumonia, in addition to the itchy rash.

Diagnosis

The condition can be diagnosed by microscopic inspection of feces which can reveal hookworm eggs. In addition visual inspection of the skin would reveal telltale itchy red lines and blisters.

Treatment

People without intestinal symptoms do not need treatment, since the worms will eventually die or be excreted. Thiabendazole or albendazole are used to treat the infestation. Mild infections can be treated by applying one of the drugs to the skin along the tracks and the normal skin surrounding the area. Thiabendazole also can be given internally, but taken this way it can cause side effects including dizziness, nausea, and vomiting

Prognosis

No matter how severe an infestation, with adequate treatment patients recover completely. However, if the patient scratches the lesions open, the areas can become vulnerable to bacterial infection.

Key terms

Larvae — Immature forms of certain worms.

Prevention

In the United States, the prevalence of dogs and cats with hookworms is the reason why the infective larvae are found so commonly in soil and sand. The play habits of children, together with their attraction to pets, puts them at high risk for hookworm infection and cutaneous larvae migrans.

Human hookworm infestation can be prevented by practicing good personal hygiene, deworming pets, and not allowing children to play in potentially contaminated environments.

Resources

Books

Turkington, Carol A., and Jeffrey S. Dover. Skin Deep: An A-Z of Skin Disorders, Treatments and Health. 2nd ed. New York: Facts on File, 1998.

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larva /lar·va/ (lahr´vah) pl. lar´vae   [L.] an independent, motile, sometimes feeding, developmental stage in the life history of an animal.

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larva cur´rens  a variant of larva migrans caused by Strongyloides stercoralis, in which the progression of the linear lesion is much more rapid.

cutaneous larva migrans , larva mi´grans creeping eruption; a convoluted threadlike pruritic, erythematous, papular or vesicular skin eruption that appears to migrate, caused by burrowing beneath the skin of roundworm larvae, particularly Ancylostoma larvae . Also applied to similar lesions caused by other parasites.

ocular larva migrans  infection of the eye with larvae of Toxocara canis or T. cati, which may lodge in the choroid or retina or migrate to the vitreous; on the death of the larvae, a granulomatous inflammation occurs, the lesion varying from a translucent elevation of the retina to massive retinal detachment and pseudoglioma.

visceral larva migrans  a condition due to prolonged migration of nematode larvae in human tissue other than skin; commonly caused by the larvae of Toxocara canis or T. cati, which do not complete their life cycle in humans.

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cutaneous larva migrans

n.

See creeping eruption.

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cutaneous larva migrans,

a skin condition caused by a hookworm, Ancylostoma braziliense, a parasite of cats and dogs. Its ova are deposited in the ground with the feces of infected animals, develop into larvae, and invade the skin of people, particularly bare feet, although any skin may be involved. The larvae rarely develop into adult hookworms in the human body, but as they migrate through the epidermis, a trail of inflammation follows the burrow, causing severe pruritus. Secondary infections often occur if the skin has been broken by scratching. It is the most commonly tropically acquired dermatosis. Beaches and other moist sandy areas are common locations of infection. Also called creeping eruption.

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larva

an independent, immature stage in a life cycle in which the stage is unlike the parent and must undergo changes in form and size to reach the adult stage. There may be one or several, three is common, larval stages in the one life cycle. In fish larvae are also called fry.

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larva currens

a variant of larva migrans caused by Strongyloides stercoralis, in which the linear progress of the lesions is much more rapid.

cutaneous larva migrans

creeping eruption; a convoluted, thread-like skin eruption in humans and other species which appears to migrate; caused by the burrowing beneath the skin of roundworm larvae, particularly Ancylostoma, Strongyloides and Gnathostoma spp. A. braziliense, A. caninum, B. phlebotomum can cause the disease.

ocular larva migrans

infection of the eye with the larvae of the roundworm Toxocara canis or T. cati, which may lodge in the choroid or retina or migrate to the vitreous; on the death of the larvae, a granulomatous inflammation occurs, the lesion varying from a translucent elevation of the retina to massive retinal detachment and pseudoglioma.

visceral larva migrans

a condition due to prolonged migration of larvae of animal nematodes in human tissues other than skin, commonly caused by larvae of the roundworms Toxocara canis and T. cati.