Treatment of Cutaneous Larva Migrans
For an otherwise healthy individual with cutaneous larva migrans, treat with either ivermectin 200 mcg/kg as a single oral dose OR albendazole 400 mg once daily for 3 days—both are equally effective first-line options with cure rates approaching 95-100%. 1
First-Line Treatment Options
You have two equally effective choices:
- Ivermectin 200 mcg/kg (0.2 mg/kg) as a single oral dose is the most convenient option, with cure rates of 95-100% in typical cases 1, 2
- Albendazole 400 mg once daily for 3 days is an alternative first-line option with comparable efficacy 1
The choice between these two depends primarily on convenience (single dose vs. 3 days) and availability, as both demonstrate excellent efficacy 1.
Clinical Diagnosis
Diagnosis is straightforward and clinical:
- Look for the characteristic serpiginous (snake-like), erythematous, intensely pruritic rash that migrates 1-2 cm per day 1
- Obtain history of skin contact with soil or sand potentially contaminated with dog or cat feces—beaches are implicated in 95% of cases 3
- Laboratory tests are typically normal and not needed for diagnosis 1, 3
- Eosinophilia may be present in some cases but is not required for diagnosis 1
Critical Pitfall to Avoid
Do not confuse persistent itching with treatment failure. Pruritus can persist for several days after successful parasite eradication due to ongoing inflammatory and allergic dermatitis 1. This is a common source of unnecessary retreatment.
When to Consider Retreatment
- If larvae recrudescence occurs (can happen up to 106 days post-treatment), retreatment with ivermectin is indicated 2
- Perform at least three stool examinations over three months following treatment using concentration techniques to ensure eradication 2
- For patients with multiple or extensive lesions, consider extending albendazole to 7 days (400 mg daily), which may reduce recurrence rates with 100% cure rates and no increased side effects 1
Expected Treatment Response
- Most patients (28 of 44 in one series, or 64%) are cured with a single course of treatment 3
- Approximately 25% may require a second course of therapy 3
- Complete resolution typically occurs within one week of treatment 4
Drug Metabolism and Interactions
- Ivermectin is primarily metabolized by CYP3A4, with minimal involvement of CYP2D6 and CYP2E1 2
- No dose adjustments are required for renal impairment 1
- Safety of multiple doses in severe liver disease is not established 1
Important Clinical Distinction
This condition must be distinguished from human hookworm infection (Ancylostoma duodenale and Necator americanus), which causes minimal skin symptoms but proceeds to systemic infection 5. Zoonotic hookworm larvae causing cutaneous larva migrans remain trapped in the epidermis, whereas human hookworm larvae penetrate skin and migrate internally 5.