INFECTIOUS DISEASES

Cutaneous larva migrans

Cause

  • Parasitic skin infection caused by hookworm larvae
  • Hookworm species include:
    • Ancylostoma braziliense: found in wild and domestic dogs and cats in central and southern US, Central and South America, and the Caribbean
    • Ancylostoma caninum: dog hookworm in Australia
    • Uncinaria stenocephala: dog hookworm in Europe
    • Bunostomum phlebotomum: cattle hookworm

Risk Factors

  • Affects people of all ages, sexes, and races
  • Common in tropical or subtropical regions
  • At-risk groups include:
    • Barefoot beachcombers and sunbathers
    • Children in sandpits
    • Farmers
    • Gardeners
    • Plumbers
    • Hunters
    • Electricians
    • Carpenters
    • Pest exterminators
  • Often seen during overseas holidays, rarely reported in those who haven’t traveled

Infection Mechanism

  • Parasite eggs in animal feces contaminate warm, moist, sandy soil
  • Larvae hatch and penetrate human skin through hair follicles, cracks, or intact skin
  • In humans, larvae migrate beneath the skin but rarely penetrate deeper layers

Signs and Symptoms

  • Non-specific eruption at the penetration site
  • Tingling or prickling sensation within 30 minutes of penetration
  • Snakelike tracks (2-3 mm wide) stretching 3-4 cm from penetration site, causing intense itching
  • Tracks advance daily, forming loops and tortuous tracks
  • Commonly affected sites: feet, spaces between toes, hands, knees, buttocks

Treatment

  • Self-limiting, usually resolves within 4-8 weeks without treatment
  • Anthelmintics:
    • Tiabendazole, albendazole, mebendazole, ivermectin
    • Topical thiabendazole for early, localized lesions
    • Oral treatment for widespread infection or failed topical treatment
    • Itching reduces within 24-48 hours of starting treatment
    • Lesions/tracts resolve within 1 week
  • Physical Treatments:
    • Liquid nitrogen cryotherapy
    • Carbon dioxide laser
  • Symptomatic Relief:
    • Antihistamines
    • Topical corticosteroids
  • Secondary Infection:
    • Treat with appropriate antibiotics if bacterial infection occurs

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