Migrating larva (larva migrans): causes, symptoms, diagnosis, treatment

Very close in clinical manifestations to linear migratory myiasis is "migrating larva" (larva migrans) - a skin disease caused by the larva of intestinal worms, most often hookworms (Ancylistoma brasiliense, A. ceylonicum, A. caninum). All these parasites are intestinal worms of animals, primarily dogs and cats.

In the favorable conditions of high humidity and temperature of tropical regions, worm eggs that fall on the ground with animal feces quickly turn into larvae, which penetrate human skin when it comes into contact with contaminated soil. Warm, damp sand in shaded areas is a particularly favorable place for active larvae to stay, and children playing on the ground or vacationers relaxing on the beach become the closest targets for infection. Agricultural workers, gardeners, hunters and others who come into contact with soil with exposed skin are often infected.

[ 1 ], [ 2 ], [ 3 ], [ 4 ], [ 5 ], [ 6 ], [ 7 ], [ 8 ]

Symptoms of Larva Migrans

Most often, the penetration of larvae into the skin occurs in the area of the feet and buttocks. Symptoms of migrating larva depend on the movement of larvae in the upper layers of the dermis, which cause non-specific dermatitis of a linear filiform nature up to 3 mm wide, with bizarre shapes and interlacing. The movement of the larva in the skin (occurring up to several centimeters) is accompanied by severe itching, burning, which leads to scratching, sometimes significant, and the occurrence of secondary infection. With the simultaneous penetration of several larvae, the interlacing of dermatitis threads becomes especially tangled, but the area of the skin lesion always remains to a certain extent limited, the larvae seem to "spin" in one place.

The evolution of the migrating larva is self-limited in time. The duration of the larva's stay in the skin is highly variable and depends on the type of worm. In many cases, the larvae die in the skin within 4 weeks, on the other hand, their persistence for several months is known.

Diagnosis of migrating larva

In typical cases, diagnosis of migrating larva is not difficult, but may arise in cases of significant scratching and secondary infection. Differential diagnosis of migrating larva is carried out with linear myiasis.

[ 9 ], [ 10 ], [ 11 ], [ 12 ], [ 13 ]

Treatment of larva migrans

Treatment of migrating larva consists of ivermectin in a single dose of 200 mg/kg. An alternative is topical application of 10% thiabendazole. Irrigation of the suspected location with ethyl chloride also leads to the destruction of the larva.