What causes cutaneous larva migrans?

From the Guidelines

The correct answer is D) Dog hookworm larvae. Cutaneous larva migrans is a parasitic skin infection caused primarily by the larvae of dog hookworms (Ancylostoma caninum), which penetrate human skin and migrate through the epidermis, creating characteristic serpiginous, raised, pruritic tracks, as stated in the UK guidelines for the investigation and management of eosinophilia in returning travellers and migrants 1. Humans are accidental hosts when they come into contact with soil contaminated with dog feces containing hookworm eggs that have hatched into larvae. The larvae cannot complete their life cycle in humans, so they remain trapped in the skin, causing the characteristic "creeping eruption." Some key points to consider in the management of cutaneous larva migrans include:

• Mode of transmission: Penetration of skin by dog/cat hookworm larvae, with a worldwide distribution and predominance in warmer regions 1
• Clinical presentation: Characteristic self-limiting itchy, serpiginous rash migrating at 1–2 cm per day, may be associated with eosinophilia 1
• Treatment: Ivermectin PO 200 μg/kg single dose or albendazole PO 400 mg once daily for 3 days is suggested 1 While cat hookworms (Ancylostoma braziliense) can also cause this condition, dog hookworms are the more common causative agent, as indicated by the guidelines 1. This condition is not caused by dog tapeworm larvae or through food contamination, and it typically occurs when walking barefoot on contaminated beaches or soil where dogs have defecated.

From the Research

Causes of Cutaneous Larva Migrans

• The condition is caused by hookworm larvae, which are found in the feces of infected dogs and cats 2, 3.
• The most common hookworms responsible for cutaneous larva migrans are Ancylostoma braziliense and Ancylostoma caninum 2, 3, 4.
• Humans become infected through contact with contaminated soil or sand, often by walking barefoot or sitting on a contaminated beach 2, 3.

Characteristics of Cutaneous Larva Migrans

• The lesions are characteristically erythematous, raised, and vesicular, linear or serpentine, and intensely pruritic 2, 5, 3.
• The condition is also known as creeping eruption due to the migrating nature of the larvae 2.

Treatment and Prevention

• Effective therapy includes oral albendazole and ivermectin 6, 5, 3.
• Prevention involves avoiding skin contact with potentially contaminated soil by wearing shoes and using towels and mats on the beach 3.

Relevant Answer Choice

• The correct answer is D) Dog hookworm larvae, as cutaneous larva migrans is caused by the larvae of dog and cat hookworms, with Ancylostoma braziliense and Ancylostoma caninum being the most common species responsible 2, 3, 4.