Cutaneous Larva Migrans: The Creeping Eruption Marc A. Brenner, DPM; Mital B. Patel, DPM Cutaneous larva migrans (CLM) is the most com- Hospital in Ontario, Canada, 48% of patients with mon tropically acquired dermatosis. It is caused CLM had recently traveled to Jamaica.2 CLM is an by hookworm larvae, which are in the feces of animal hookworm infestation usually caused by the infected dogs and cats. The condition occurs Ancylostoma genus of nematodes. It is confined pre- mainly in the Caribbean and New World, and dominantly to tropical and subtropical countries, anyone walking barefoot or sitting on a contami- although its distribution is ubiquitous. Eggs of the nated beach is at risk. nematode (usually Ancylostoma braziliense) are Ancylostoma braziliense and Ancylostoma found most commonly in dog and cat feces. In caninum are the most common hookworms Uruguay, 96% of dogs are infected by hookworms.3 responsible for CLM. The lesions, called creep- An individual is exposed to the larvae by sitting or ing eruptions, are characteristically erythema- walking on a beach that has been contaminated tous, raised and vesicular, linear or serpentine, with dog or cat feces. In a retrospective survey of and intensely pruritic. The conditions respond to 44 cases of CLM presented at the Hospital for oral and/or topical application of thiabendazole. Tropical Diseases in London, 95% of patients Humans become an accidental dead-end host reported a history of exposure at a beach.4 Activi- because the traveling parasite perishes, and its ties that pose a risk include contact with contami- cutaneous manifestations usually resolve nated sand or soil, such as playing in a sandbox, uneventfully within months. walking barefoot on a beach, or working in crawl Cutis. 2003;72:111-115. spaces under houses. Furthermore, carpenters, elec- tricians, plumbers, farmers, ranchers, gardeners, utaneous larva migrans (CLM), creeping pest exterminators, groundskeepers, and laborers eruptions, creeping verminous dermatitis, are at an increased risk of acquiring CLM. C sandworm eruptions, plumer’s itch, and duckhunter’s itch are all terms that describe a clin- Etiology ical finding caused by several different parasites. Although CLM may be caused by a myriad of nema- CLM was first described in 1874. It has the most todes, the most common infective agents are A frequent serpiginous lesions seen in travelers and is braziliense and Ancylostoma caninum.5 A braziliense the most common tropically acquired dermatosis. is a hookworm that infests wild domestic dogs CLM is rated second to pinworm among helminth and cats and can be found in the central and infections in developed countries.1 southern United States, Central and South Most cases of CLM in North America and America, and the Caribbean. A caninum is an Europe involve travelers returning from tropical Australian dog hookworm. Other causes include areas or hot climates, such as Africa, Latin America, Uncinaria stenocephala (European dog hookworm) the Caribbean, Southeast Asia, and even the south- and Bunostomum phlebotomum (cattle hookworm). eastern United States. In a review of 60 cases pre- Rare etiologies include Ancylostoma ceylonicum, sented to the Tropical Disease Unit of the Toronto Ancylostoma tubaeforme (cat hookworm), Strongyloides papillosus (parasite of sheep, goat, and cattle), and Strongyloides westeri (parasite of horses).1 Accepted for publication May 30, 2003. Adult hookworms release eggs while in the Dr. Brenner is from Long Island Jewish/North Shore Hospital, intestines of their hosts—dogs and cats. The eggs Manhasset, New York. Dr. Patel is from Passaic Beth Israel are passed through the stool onto warm sandy soil, Hospital, New Jersey. The authors report no conflict of interest. which serves as a rich incubator (Figure 1). The Reprints: Mital B. Patel, DPM, 107 Wortendyke Ave, Emerson, NJ eggs feed on soil bacteria and mature into nonin- 07630 (e-mail: [email protected]). fectious rhabditiform larvae and subsequently into VOLUME 72, AUGUST 2003 111 Cutaneous Larva Migrans Figure 1. Life cycle of the larva. Graphic design by Taino Soba. infectious filariform larvae.6 These larvae become situate 1 to 2 cm ahead of the tract, which helps infectious after 2 months and acquire the ability to explain why local invasive treatment aimed at the penetrate the skin of a new host. Humans are acci- tract is often ineffective.11 dental hosts, who come in contact with soil con- Lesions are characterized clinically by an almost taminated with animal defecation. After contact, pathognomonic creeping eruption, which is the infectious larvae penetrate the epidermis of intensely pruritic. Patients often report a tingling intact skin by means of proteases. Hookworm larvae or prickling sensation. The lesions are characteris- also can enter through broken skin or hair follicles.7 tically erythematous, raised and vesicular, and lin- It is believed that the larvae lack the collegenase ear or serpentine (Figure 2). Lesions can be single required to penetrate the basement membrane to or multiple and may be painful. They are approxi- invade the dermis1; therefore, the larvae are mately 3 mm wide and may reach 15 to 20 cm in blocked in the epidermis but still are able to move length. The penetrating larvae advance from a few around (probably through the secretion and pro- millimeters to a few centimeters a day. The larvae duction of hyaluronidase).8 After entering the epi- move ahead of the tracts, and vesicles may form in dermis, the larvae wander aimlessly through the the tract as the worm changes direction. These skin. This migration, from the time of penetration vesicles become thick and encrusted.12 Sinuous to the onset of symptoms, can vary in length from inflammatory trails may be clearly visible on the days to weeks.7 In a review, the mean period surface of the skin. The areas most frequently between exposure, penetration, and onset of symp- affected by infectious larvae are the dorsal and toms was 2 to 50 days.9 The movement of hook- plantar aspects of the foot and interdigital spaces worm larvae causes a distinct lesion in the form of between the toes.2 The buttocks is also a common a highly pruritic, linear, serpiginous eruption. Tissue area of eruption, especially in young children, reaction is delayed 24 to 48 hours.10 The larvae because the larvae have been shown to penetrate 112 CUTIS® Cutaneous Larva Migrans AB Figure 2. The lesions of cutaneous larva migrans are characteristically erythematous, raised, and linear or serpentine (A and B). thin clothing such as bathing suits. Other areas less history of visiting beaches, being near uncovered frequently affected include the arms and breasts.7 sandboxes, or working in an occupation conducive Excoriation and impetiginization are common. to exposure. Laboratory results may include a tran- Systemic signs and symptoms (eg, wheezing, dry sient peripheral eosinophilia on a complete blood cough, urticaria) have been reported in patients count and increased IgE levels on total serum with extensive infection. A caninum larvae can immunoglobulins. The intractable pruritus may be migrate to the gastrointestinal tract, causing related to eosinophilia or elevated levels of IgE, human eosinophilic enterocolitis, a relatively rare which may be persistently abnormal up to 4 weeks condition that leads to acute abdominal pain, after treatment of the infestation.15,16 Results of a anorexia, nausea, and diarrhea. A caninum larvae skin biopsy taken just ahead of the leading edge also migrate into the dermis and enter the circula- of a tract may show larvae (stained positive with tion, thus causing Löffler syndrome, which is char- periodic acid–Schiff) in a suprabasalar burrow, acterized by asthma, pulmonary infiltrate, basal layer tracts, spongiosis with intraepidermal eosinophilia, fever, polmorphous erythema, and vesicles, necrotic keratinocytes, and an epidermal occasionally urticaria.12-14 Löffler syndrome may and upper dermal chronic inflammatory infiltrate accompany the cutaneous eruption. with many eosinophils. However, detection of the Diagnosis of CLM is based on characteristic causative pathogen by skin biopsy is difficult clinical findings of the eruption and known because of the rapid movement of the larvae. epidemiologic exposure. It is important for clini- The differential diagnosis of CLM includes cer- cians to obtain a full travel history, including a carial or contact dermatitis, bacterial or fungal VOLUME 72, AUGUST 2003 113 Cutaneous Larva Migrans infections, scabies, lichen planus, myiasis, loiasis, Prognosis is excellent for CLM. CLM is a self- or other migratory parasites. limiting disease but can last for up to 2 years.25 Prior to the 1960s, topical modalities such as Humans are accidental dead-end hosts with the ethyl chloride spray, liquid nitrogen, phenol, CO2 larvae dying and lesions resolving within 4 to snow, peperazine citrate, faudin, electrocautery, and 8 weeks and, in rare cases, as long as 1 year. even x-ray therapy were used unsuccessfully because the larvae were often missed and/or not killed. Conclusion Chemotherapy with chloroquine, antimony, and Knowledge of the life cycle of dog and cat hook- diethyl carbamazine also were attempted, with sim- worms and the clinical manifestations of their ilar haphazard results.1 infestation of human skin is vital to instituting Currently, treatment of CLM includes thiaben- prompt treatment. The clinician should take a dazole, ivermectin, mebendazole, or albendazole. complete travel history including review of initial Thiabendazole was first used in 1963 by Stone and presentation of symptoms, pattern of rash, location Mullins.17 The treatment of choice in the United of lesions, course of symptoms, any previous States is the cutaneous application of 10% to attempts at treatment, and whether any family 15% thiabendazole cream, made by crushing a members are affected. Patient education is critical 500-mg tablet of thiabendazole in 5 g of a water- for preventing CLM. Patients should be advised to soluble cream or by using an oral thiabendazole avoid walking barefoot when visiting tropical suspension topically.