Creeping eruption

The dog and cat hookworm eggs found in the stool of these animals will hatch, and the larvae then infest the soil and vegetation around the droppings. When human skin comes in contact with the infested soil, the larvae burrow into the skin, causing an intense inflammatory response that follows their progress beneath the skin and leads to severe itching. A visible path that marks the migratory trail of the larvae is often seen. The larvae may migrate at rates of a few millimeters to a few centimeters per day.

Creeping eruption is caused chiefly by Ancylostoma braziliense, the hookworm of the dog or cat. Ova are deposited on the ground in dog or cat feces. Larvae persist in warm moist ground or sand and penetrate unprotected skin that contacts the soil. Infection most commonly involves the feet, legs, buttocks, or back. As the parasite burrows into the epidermis, it produces a winding, threadlike trail of inflammation. Pruritus is marked. Scratch dermatitis and bacterial infection may complicate the otherwise typical serpiginous lesion.

Applying the oral 10% suspension of thiabendazole topically to all affected areas qid for 7 to 10 days is promptly effective. Topical mebendazole incorporated into cream is also said to be effective. Public sanitation has decreased the incidence of hookworm infestation in the United States. De-worming of cats and dogs can reduce the incidence among these animals. Wearing shoes in endemic areas (areas where hookworm infections are known to occur frequently) will prevent penetration of the larvae through the feet (a common site).

Creeping eruption is the common term for cutaneous larva migrans, which is caused by the larvae of hookworms that infest cats and dogs. Humans pick up the larvae upon exposure to dirt, particularly moist, sandy soils following a rainfall. The larvae invade the skin, most commonly on the feet, lower legs, hands, and buttocks (from sitting). The larvae tunnel through the top layer of skin, leaving a serpentine, threadlike trail of inflamed (red) tissue, which itches and may be slightly painful. Treatment is with topical thiabendazole four times a day for two weeks. If the topical medication is not available, thiabendazole can be administered in an oral form in a dose of 22 milligrams per kilogram (2.2 pounds) of body weight, not to exceed 1.5 grams per dose, twice a day for two days. If the rash doesn't completely resolve within 48 hours after therapy, repeat the treatment.