Medication Summary

In general, blood eosinophilia combined with a positive serologic test result indicates active toxocariasis and requires treatment. Deciding whether to treat covert or subclinical toxocariasis that does not show eosinophilia is controversial. Consider treatment in patients with a total serum IgE level over 500 IU/mL. Mebendazole or diethylcarbamazine kills the nematode larvae. Prednisone can be used as an adjunct to antihelmintic therapy in patients with wheezing or other signs of tissue inflammation.

Class Summary

These agents are specific to nematode infection.

Mebendazole (Vermox)

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DOC. Adverse effects are negligible, except headaches during early therapy. These symptoms are from metabolites secreted from nematodes that are killed by the drug. Causes worm death by selectively and irreversibly blocking uptake of glucose and other nutrients in susceptible adult intestines where helminths dwell.

Albendazole (Albenza)

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Second DOC if mebendazole is difficult to obtain. Decreases ATP production in the worm, causing energy depletion, immobilization, and, finally, death.

Diethylcarbamazine citrate (Hetrazan)

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Synthetic organic compound highly specific for several common parasites. Does not contain any toxic metallic elements. Not recommended as the DOC because of more severe adverse effects. Recommended if therapy with mebendazole fails or mebendazole is not available.

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Media Gallery

The image on the left is a posteroanterior chest radiograph in a patient with toxocariasis. The image on the right is a CT scan of the patient with toxocariasis showing multiple pulmonary nodules with surrounding ground-glass opacities at first visit.
Funduscopic examination of the right eye of a patient with ocular toxocariasis showing rhegmatogenous retinal detachment.
Immunogold finding of Toxocara canis larva reacted with a seropositive human serum. Arrows indicate each particle. (A) High-density immunogold particles are distributed in the large columnlike secretory cell (LCSC), excretory duct (ED), and cuticle(C); (B) high-density immunogold particles are shown in the secretory cell (SC), excretory duct (ED), and cuticle; (C) immunogold particles are distributed in the excretory duct (ED); (D) high-density particles are displayed in the microvilli of the intestine (MI); (E) immunogold particles are shown in the excretory duct; and (F) high-density immunogold particles are distributed in the cuticle(C).