GENERAL CHARACTERISTICS
Ancylostoma braziliense and Anycylostoma caninum are common hookworms of dogs and cats. The parasites penetrate the skin and cause cutaneous larva migrans (CLM), also referred to as creeping eruption.
EPIDEMIOLOGY
The organisms are found in warm climates within the Southeastern United States. Dogs and cats are the natural definitive host for Ancylostoma spp. The infective larvae penetrate the skin of the host and migrate in the circulation. The adult worms reside in the intestine. The eggs are shed in the feces of dogs and cats. The eggs undergo maturation in moist, sandy soil in areas protected from desiccation, such as under shady trees and houses. Children are often infected when playing in sandboxes that have been contaminated with dog and cat feces.
PATHOGENESIS AND SPECTRUM OF DISEASE
The infective larvae penetrate the skin of the human host and migrate through the subcutaneous tissue. The host develops pruritic papules at the site of penetration, followed by serpiginous, vesicular, elevated linear tracks. The larvae will migrate several millimeters each day, forming these continued tracks. The area surrounding the tracks becomes inflamed with marked edema. The patient may present with a peripheral eosinophilia. Infection is typically self-limiting. As the larvae migrate, the host may scratch and scar the tissue, subjecting the host to potential secondary bacterial infections. The signs and symptoms resemble those of infection with similar insect larvae, Strongyloides stercoralis, and other animal hookworms.
Systemic involvement is rare; however, cases of pneumonitis resulting from larvae migration into the lungs have been identified. In addition, gastrointestinal discomfort including abdominal pain, diarrhea, and weight loss has been associated with Ancylostoma spp. infections. This condition is referred to as eosinophilic enteritis.
See Table 1 for a summarized detail of associated diseases.
Table1. Pathogenesis and Spectrum of Associated Diseases
LABORATORY DIAGNOSIS
Laboratory diagnosis is limited. Evidence of visible tracks and patient history of possible exposure are usually sufficient. The patient may present with a peripheral eosinophilia. In systemic cases, larvae may be recovered from sputum and Charcot-Leyden crystals may be evident.
THERAPY
Anthelmintic therapy may include ivermectin or thiabendazole.
