Cutaneous Larva Migrans

Cutaneous larva migrans is a superficial parasitic skin infection caused by animal hookworm larvae, most commonly from dogs or cats. Humans are accidental dead-end hosts. Infection usually follows barefoot skin contact with contaminated sand or soil, especially after travel to tropical or subtropical areas.

⚠️ Risk Factors

• Recent travel to tropical or subtropical regions
• Walking barefoot on beaches or contaminated soil
• Sitting or lying directly on sand
• Exposure to dogs, cats or animal faeces
• Poor sanitation in endemic areas

🔍 Clinical Features

• Intensely itchy, serpiginous or “creeping” rash
• Raised erythematous track that slowly migrates
• Commonly affects feet, buttocks, thighs or hands
• Usually appears days to weeks after exposure
• Excoriation, impetiginisation or cellulitis may occur

The key clue is a very itchy, winding, migratory track after travel or soil/sand exposure. Larvae penetrate the epidermis but cannot complete their life cycle in humans, so the infection is usually limited to the skin.

🤔 Differential Diagnosis

• Scabies
• Tinea corporis
• Contact dermatitis
• Urticaria
• Insect bites
• Larva currens from strongyloidiasis
• Impetigo or cellulitis if secondarily infected

🧪 Investigations

• Usually a clinical diagnosis
• Ask about travel, beach exposure, barefoot walking and animal contact
• Skin biopsy is rarely helpful as the larva is usually ahead of the visible track
• Consider bacterial swab if crusting, discharge or cellulitis
• Consider specialist advice if diagnosis is uncertain or strongyloidiasis is possible

✅ Management

• Reassure that cutaneous larva migrans is usually self-limiting
• Treat symptomatic, extensive, persistent or cosmetically troublesome disease
• Oral ivermectin or albendazole are commonly used anthelmintic options
• Use BNF, local formulary and specialist guidance for dosing
• Treat secondary bacterial infection according to local antimicrobial guidance
• Offer antihistamines or topical corticosteroid for itch if needed

CDC guidance describes cutaneous larva migrans as often self-limiting because larvae usually die after several weeks, but albendazole or ivermectin can be curative and may be used to shorten symptoms. DermNet similarly notes that treatment reduces itch rapidly and most lesions resolve within about a week after effective anthelmintic therapy. :contentReference[oaicite:0]{index=0}

💊 Treatment Notes

• Albendazole may be used for several days depending on local guidance
• Ivermectin is often used as single-dose or short-course therapy
• Avoid ivermectin in pregnancy unless specialist advised
• Check age, weight, pregnancy status, liver disease and drug interactions
• Seek specialist advice for children, pregnancy, immunosuppression or treatment failure

🚩 Refer or Seek Advice

• Diagnostic uncertainty
• Extensive or recurrent lesions
• Failure of initial treatment
• Pregnancy or breastfeeding
• Young child or low body weight
• Possible strongyloidiasis or systemic parasitic infection
• Cellulitis, systemic symptoms or severe secondary infection

🧠 Clinical Pearls

• Think “itchy travelling line after travel”
• Feet and buttocks are classic sites
• The larva is usually ahead of the visible end of the track
• Cryotherapy is generally unreliable because the larva is hard to localise
• Larva currens moves much faster and suggests Strongyloides

⚕️ Disclaimer

This article is for clinician education and revision. Management should follow current BNF, local antimicrobial or parasitology guidance, patient-specific contraindications, and specialist infectious diseases or dermatology advice where needed.