Clinical findings suggestive of toxocariasis:
(1) eosinophilia (may be absent in ocular larva migrans)
(2) fever
(3) ocular involvement (larvae may be visible; may present as a unilateral, raised gray or white fundic lesion)
(4) hepatomegaly
(5) pneumonitis with cough and pulmonary infiltrates
If the person has had exposure to dogs or cats, then serologic tests for toxocariasis should be ordered. Biopsy is not usually necessary for diagnosis and is not usually recommended.
If serologic tests are negative, then the diagnosis of toxocariasis is unlikely. In a patient with findings compatible with larve migrans then other nematodes in the differential diagnosis should be considered.
If serologic tests are positive, then toxocariasis is likely.
The presence of toxocariasis does not exclude other parasites such as Ascaris or Trichuris.
