toxocariasis

toxocariasis /tok′sōkərī″əsis/ [Gk, toxo, bow, kara, head, osis, condition] , infection with the larvae of Toxocara canis, the common roundworm of dogs, and with T. cati, of cats. Human ingestion of viable eggs, commonly found in soil, leads to the spread of tiny larvae throughout the body, resulting in respiratory symptoms, enlarged liver, skin rashes, eosinophilia, and delayed ocular lesions. Children who eat dirt are particularly subject to this disease. Specific drug therapy is not very useful; the outcome is usually good without therapy. Two major forms of the infection exist: ocular larval migrans (OLM), which can cause an eye disease resulting in blindness, occurs when the worm enters the eye. Visceral larval migrans (VLM) is heavy or repeated infection that causes swelling of organs or the central nervous system. Symptoms of this form are caused by movement of the worms and are manifested as fever, asthma, or pneumonia. Severe forms are rare. VLM is treated with antiparasitic drugs and antiinflammatories, whereas OLM is more difficult to treat and usually involves preventing progression of eye damage. Regular worming of pets helps prevent infection. Also called visceral larva migrans.