Got the Travel Bug? A Review of Common Infections, Infestations, Bites, and Stings Among Returning Travelers

Matthew P. Vasievich; Jose Dario Martinez Villarreal; Kenneth J. Tomecki

Disclosures

Am J Clin Dermatol. 2016;17(5):451-462. 

In This Article

Cutaneous Larva Migrans

Pathophysiology

Cutaneous larva migrans is a skin disease caused by the hookworms Ancylostoma braziliense, Ancylostoma caninum, and Uncinaria stenocephala, natural parasites of dogs and cats. Humans are a dead-end host. The worms themselves are approximately 0.5 mm in diameter, but are occasionally longer. The parasites are excreted in the host animal feces, often on soil or sand (beaches) and subsequently acquired by direct skin contact with individuals laying out on beaches or walking barefoot along the water. The worms invade the skin but lack a secreted collagenase enzyme required to penetrate the basement membrane and thus become trapped in the epidermis, which results in serpiginous erythema and pruritus.[5]

Epidemiology

Cutaneous larva migrans is one of the most common skin diseases seen in returning travelers, accounting for about 10 % of all skin disease. It is most often acquired on beaches in Asia, Africa, South and Central America, and the Caribbean.[3]

Clinical Presentation

The incubation period for the disease is 5–15 days, after which extremely pruritic linear or serpiginous erythematous tracts appear, which represent the path of single larva through the epidermis (Fig. 2). The tracts are most commonly found on the feet, followed by the thighs and legs or buttocks. The average number of tracts per patient is three. The rate of progression of the path is approximately 2–3 cm/day. The parasite in the skin causes a hypersensitivity reaction in the host, which causes the pruritus. Laboratory findings can include peripheral eosinophilia and elevated serum immunoglobulin (Ig)-E. Differential diagnosis includes pili migrans, migratory myiasis, larva currens, scabies, gnathostomiasis, and strongyloidiasis. The diagnosis of cutaneous larva migrans is made clinically. There have been reports of dermoscopy and confocal scanning laser microscopy being used to aid in identifying the worms, though the sensitivity of these techniques has not yet been established. Possible complications include superinfection/impetiginization, bullae, and papular urticaria.[6] Loffler's syndrome is a systemic disease of unknown etiology that consists of migratory pulmonary infiltrates and peripheral eosinophilia. In rare cases, it has been associated with cutaneous larva migrans. Whether this represents direct invasion of the lungs by the worm or a systemic response to the infestation is yet to be determined.[7]

Figure 2.

Cutaneous larva migrans

Treatment

Cutaneous larva migrans is a self-limited disorder that usually resolves within 2–3 months as the parasites die within the epidermis. As such, treatment may not be necessary though will likely be desired by most patients. A single dose of ivermectin (12 mg in adults, 150 μg/kg in children) is curative in 80–100 % of cases; alternatives are albendazole 400 mg as a single dose or topical thiabendazole 10–15 % three times daily for 15 days. Cryotherapy of the advancing edge of the tracts is not usually effective.[8]

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