Fast Facts: cutaneous larva migrans Cutaneous larva migrans (CLM) is a common parasitic skin infection in travellers returning from tropical or subtropical regions. It is caused by the larvae of animal hookworms, most commonly Ancylostoma braziliense and Ancylostoma caninum , which penetrate human skin but cannot complete their life cycle. CLM is intensely pruritic and often distressing, particularly in children.
While the condition is self-limiting, treatment is recommended to reduce symptom duration and prevent secondary bacterial infection. The choice of treatment depends on the child’s age and weight, with topical therapy preferred for younger children.
Clinical features
CLM presents as:
Pruritic, serpiginous (wavy or linear) tracks on the skin, typically on the feet, buttocks, or thighs but can also appear on the face and trunk.A small red papule at the site of larval entry, followed by progressively extending, raised lesions.Slow migration of the lesion at a rate of millimetres to centimetres per day.Intense itching , which is often worse at night.
Unlike human hookworm infections, CLM does not cause systemic symptoms such as fever or eosinophilia.
Epidemiology
CLM is endemic in tropical and subtropical regions , including:
The Caribbean – Jamaica, the Bahamas, the Dominican RepublicSouth and Central America – Brazil, Colombia, Mexico, Costa RicaSoutheast Asia – Thailand, Indonesia (Bali), the PhilippinesAfrica – Kenya, South Africa, GhanaOceania – Northern Australia, Fiji
UK cases occur almost exclusively in travellers who have had direct contact with contaminated sand or soil in these regions, particularly children playing on the beach.
Diagnosis
CLM is diagnosed clinically based on:
Recent travel to an endemic area A characteristic pruritic, migratory skin lesion A history of barefoot exposure to sand or soil
No laboratory tests are required. Dermoscopy may show translucent tunnels, but biopsy is unnecessary.
Differential diagnosis
Conditions that mimic CLM include:
Scabies – Burrows in web spaces, wrists, and axillae, with nocturnal itching.Larva currens (Strongyloidiasis) – Rapidly moving lesions, systemic symptoms, and eosinophilia.Tungiasis – Localised nodules on the feet caused by Tunga penetrans (sand flea).Contact dermatitis – Well-demarcated, often vesicular rash without migration.
Management in children
The treatment approach for CLM in children depends on age and weight.
First-line treatment for young children (<15 kg or under 2 years old)
Topical thiabendazole 10–15% cream , applied 3 times daily for 5–7 days .If topical thiabendazole is unavailable, cryotherapy with liquid nitrogen may be an option, although it is less effective and can be painful.
First-line treatment for older children (>15 kg or over 2 years old)
Oral albendazole – effective and generally well-tolerated.
Symptomatic relief
Topical corticosteroids (eg, hydrocortisone 1%) to reduce inflammation and itching.Oral antihistamines (eg, cetirizine) for pruritus.Emollients to prevent excessive skin irritation.Antibiotics if secondary bacterial infection occurs due to scratching.
Without treatment, lesions persist for weeks to months but eventually resolve.
Patient education
Preventing infection
Parents should be advised to:
Keep children’s feet covered with sandals or water shoes on beaches in tropical regions.Use beach mats or towels when sitting or lying on sand.Avoid areas contaminated with animal faeces.
Recognising symptoms early
Families should be aware of the characteristic migratory rash and seek medical advice if lesions develop after returning from a tropical holiday.
Reassurance
CLM is not a serious or systemic infection and is easily treatable .
With treatment, symptoms resolve within a few days .
chat gbt is admirably thorough and can produce long detailed articles in seconds. Take note would be medical journalists!