Toxocariasis

Introduction 

Toxocariasis is due to human infection with Toxocara cati (an intestinal parasite of cats) or Toxocara canis (an intestinal parasite of dogs)

-Most commonly encountered among children 1 to 6 years of age 

-Transmission to humans by ingestion of eggs in soil, particularly in those with a history of pica

-Invading larvae migrate in human tissues and cannot mature to adult worms 

Symptoms & Signs 

A. Visceral larva migrans: it is due to disseminated systemic infection; It mostly affects the liver, lungs, heart, skeletal muscle and brain; eosinophilic granulomas surround parasite larvae

Pulmonary: Cough, wheezing, pulmonary infiltrates 

Abdominal: The most commonly affected organ is the liver; hepatomegaly, splenomegaly 

Heart: Myocarditis, pericarditis, cardiac arrhythmia

decreased visual acuity 

B. Ocular Larva Migrans

Unilateral posterior or peripheral inflammatory eye mass, granuloma formation, blurred vision, red eye, a whitish pupil due to loss of red reflex (leukocoria), unilateral strabismus

Diagnosis 

Labs: Leukocytosis with marked eosinophilia, anemia, and elevated liver function tests

Serology: ELISA, Western blot 

Liver biopsy: Demonstration of larva 

Treatment 

-It is usually a benign and self-limited illness 

-Severe disease: Albendazole, mebendazole, corticosteroids