Basics
Description
Infestation of the epidermis by the infectious larvae of certain nematodes, classically manifesting with an intensely pruritic, serpiginous skin lesion
Epidemiology
Worldwide distribution, but most frequent in warmer climates, including the Caribbean, Africa, South America, Southeast Asia, and southeastern United States
Risk Factors
- Contracted from soil contaminated with dog and cat feces
- Occupational exposures occur from crawling under buildings, such as among plumbers and pipefitters.
Pathophysiology
- Route of spread
- Primary host (dog or cat) passes eggs to ground through feces.
- Warm, sandy soil acts as an incubator.
- Eggs mature into rhabditiform larvae (noninfectious), which molt in 5 days to filariform larvae (infectious).
- Humans are accidental hosts.
- Filariform larvae penetrate the epidermis either through hair follicles or fissures or through intact skin with the use of proteases.
- Larvae are unable to penetrate the basement membrane of the dermis; therefore, the infection remains limited to the epidermis.
- Larvae cannot complete their life cycle in the human host and die within weeks to months.
- Symptoms are due to hypersensitivity to the organism or its excreta.
Etiology
- Most common organism is the dog or cat hookworm, Ancylostoma braziliense.
- Other species include Ancylostoma caninum, Uncinaria stenocephala, and Bunostomum phlebotomum.
Diagnosis
- Diagnosis is usually clinical. Organisms are rarely recovered from biopsy and antibody titers are unreliable.
History
- Incubation period
- Usual time from infectious exposure to symptoms is 7-10 days but may last for up to several months.
- Rash
- Intensely pruritic, raised, serpiginous, and linear
- Most commonly located on feet, buttocks, and abdomen; also found on face, extremities, and genitalia
- Pruritus
- Symptoms typically begin with some tingling in the affected area with the development of the typical rash with intense pruritus.
- Speed at which rash spreads
- Rash typically lengthens by a few millimeters to 2-3 cm daily.
- Source of infection
- History of contract with beaches in tropical countries where dogs are frequently found
- In the United States: most frequently contracted from moist soil in southeastern United States contaminated with animal feces
Physical Exam
The classic rash is described as an erythematous, raised, serpiginous rash. In addition, it may begin as vesicular and/or form bullae along the track. Tracks under the skin reflect the course of the larvae. The active end is not part of the track.
Diagnostic Tests & Interpretation
Lab
- Biopsy: not indicated because it rarely yields organisms
- Serologic testing: not helpful and unreliable, as immunity does not usually develop
- Diagnosis is based on clinical presentation.
Differential Diagnosis
- Cutaneous larva migrans should be considered in anyone with an intensely pruritic, raised, serpiginous, linear cutaneous eruption.
- Hookworm infections
- Strongyloides stercoralis
- U. stenocephala
- B. phlebotomum
- Gnathostoma spinigerum
- Free-living nematodes (Pelodera strongyloides) and insect larvae
- Other cutaneous eruptions that may mimic cutaneous larva migrans include the following:
- Scabies
- Tinea pedis
- Erythema migrans of Lyme disease
- Jelly fish stings
- Contact dermatitis
- Photosensitivity
Treatment
General Measures
- Albendazole
- First line
- Administered as 400 mg PO once a day for 3 days
- Ivermectin
- 200 mcg/kg once a day for 1-2 days
- Oral ivermectin is contraindicated in children who weigh less than 15 kg or are younger than 5 years old.
- Alternative: topical thiabendazole 10-15% applied three times a day for 5-7 days; not readily available for prescription
Ongoing Care
Follow-up Recommendations
Patient Monitoring
- Symptoms persist for 8 weeks but up to 1 year in untreated patients.
- Those with extensive involvement should be seen after treatment to be certain of improvement in symptoms.
Prognosis
- This is a self-limited disease and will resolve without treatment when the larvae die.
- Cure rates with oral ivermectin range from 77 to 100% after one dose, with a second dose usually providing complete resolution. Oral albendazole for 5-7 days has cure rates of 92-100%.
Complications
- Most common complication is secondary bacterial infection of the involved skin.
- Self-limited disease: If untreated, larvae die within 2-8 weeks but may persist for up to 1 year.
- Rarely, the larvae can invade the dermis and, subsequently, the bloodstream, leading to a peripheral eosinophilia and pulmonary infiltrates (L ¶ffler syndrome).
Additional Reading
- Blackwell V, Vega-Lopez F. Cutaneous larva migrans: clinical features and management of 44 cases presenting in the returning traveler. Brit J Dermatol. 2001;145(3):434-437. [View Abstract]
- Bouchaud O, Houze S, Schiemann R, et al. Cutaneous larva migrans in travelers: a prospective study, with assessment of therapy with ivermectin. Clin Infect Dis. 2000;31(2):493-498. [View Abstract]
- Brenner MA, Patel MB. Cutaneous larva migrans: the creeping eruption. Cutis. 2003;72(2):111-115. [View Abstract]
- Caumes E. Treatment of cutaneous larva migrans. Clin Infect Dis. 2000;30(5):811-814. [View Abstract]
- Heukelbach J, Feldmeier H. Epidemiological and clinical characteristics of hookworm related cutaneous larva migrans. Lancet Infect Dis. 2008;8(5):302-309. [View Abstract]
- Tan SK, Liu TT. Cutaneous larva migrans complicated by L ¶ffler syndrome. Arch Dermatol. 2010;146(2):210-212. [View Abstract]
Codes
ICD09
- 126.9 Ancylostomiasis and necatoriasis, unspecified
- 126.2 Ancylostomiasis due to ancylostoma braziliense
- 126.9 Ancylostomiasis and necatoriasis, unspecified
ICD10
- B76.9 Hookworm disease, unspecified
- B76.8 Other hookworm diseases
SNOMED
- 278041003 Larva migrans of skin (disorder)
- 22728002 Ancylostomiasis due to Ancylostoma braziliense (disorder)
FAQ
- Q: Can children spread the infection to each other?
- A: The usual spread of infection is from direct contact with the larvae. Person-to-person spread does not occur.
- Q: What is the role of treatment in cutaneous larva migrans?
- A: Although the infestation is self-limited, as the larvae die with time, antiparasitic therapy helps to control the symptoms and prevent complications such as secondary bacterial infection.
- Q: What are preventive strategies for avoiding cutaneous larva migrans when visiting tropical beaches?
- A: When on tropical beaches frequented by dogs, wear shoes, avoid lying directly on dry sand, and only lie in sand that has been washed by the tide.
- Q: What are other names for cutaneous larva migrans?
- A: Creeping eruption, sandworms, and plumber's itch