What is the treatment for Toxocara infection?

Treatment of Toxocariasis

The first-line treatment for Toxocara infection is albendazole 400 mg twice daily for 5 days for visceral larva migrans, and albendazole 400 mg twice daily for 2 weeks combined with corticosteroids for ocular toxocariasis. 1

Clinical Forms and Treatment Approach

Visceral Larva Migrans (VLM)

• Albendazole 400 mg twice daily for 5 days is the recommended first-line treatment for VLM 1
• For severe VLM, adding prednisolone 40-60 mg daily may be necessary to control inflammation 1
• Monitoring complete blood count and liver enzymes is essential at the beginning of treatment and every 2 weeks during therapy due to risk of bone marrow suppression and hepatotoxicity 2

Ocular Toxocariasis

• Treatment requires a combination approach with albendazole 400 mg twice daily for 2 weeks plus corticosteroids 3, 1
• Joint management with ophthalmology is essential for optimal outcomes 3
• Corticosteroid therapy is crucial to control inflammation in ocular disease 3, 4
• In cases with significant vitreous involvement, intravitreal injections or vitrectomy may be considered 3

Neurotoxocariasis

• Treatment includes albendazole for 3-4 weeks, with corticosteroids added in cases with significant inflammation 1
• Patients being treated for neurotoxocariasis should receive steroid and anticonvulsant therapy to prevent neurological symptoms 2

Congenital Toxocariasis

• The preferred treatment for congenital toxocariasis is pyrimethamine (loading dose of 2 mg/kg body weight/day for 2 days, then 1 mg/kg/day for 2-6 months, followed by 1 mg/kg administered three times a week) combined with sulfadiazine (50 mg/kg/dose twice daily), with supplementary leucovorin (folinic acid) 5
• The recommended duration of treatment is 12 months 5

Dosing Considerations

Adults

• Standard dose: Albendazole 400 mg twice daily 1, 2
• Duration: 5 days for VLM, 2 weeks for ocular disease, 3-4 weeks for neurotoxocariasis 1

Children

• Albendazole 15 mg/kg/day divided into two doses (not to exceed adult dose) 6
• Children <5 years are at higher risk for toxocariasis and dosing should be adjusted by weight 7

Monitoring During Treatment

• Complete blood count should be performed at the beginning of treatment and every 2 weeks while on therapy 2
• Monitor liver enzymes (transaminases) before starting treatment and at least every 2 weeks during treatment 2
• Patients with liver disease are at increased risk for bone marrow suppression and warrant more frequent monitoring 2
• Discontinue albendazole if clinically significant decreases in blood cell counts occur or if liver enzymes are significantly elevated 2

Special Considerations

Pregnancy

• Pregnancy testing is recommended for females of reproductive potential prior to initiating albendazole 2
• Albendazole should ideally be avoided during pregnancy, especially first trimester, due to potential embryo-fetal toxicity 7, 2
• Females of reproductive potential should use effective contraception during treatment with albendazole and for 3 days after the final dose 2

Immunocompromised Patients

• HIV-infected children with acquired CNS, ocular, or systemic toxoplasmosis should be treated with pyrimethamine and leucovorin plus sulfadiazine for 6 weeks 5
• Immunocompromised patients may require more aggressive treatment and monitoring 7

Treatment Efficacy Evaluation

• Evaluation of treatment efficacy can be made by observing a rise in eosinophilia within a week followed by improvement in clinical symptoms 6
• Lower eosinophilia and serological titers should be monitored over a period of at least 4 weeks 6
• High IgG titers after treatment suggest ineffective therapy requiring subsequent treatment 8

Common Pitfalls and Caveats

• Ocular toxocariasis may occur without systemic eosinophilia, making diagnosis challenging 3, 1
• Once larvae have reached the brain and musculature (after 7-8 days of infection), they may be less susceptible to anthelmintic agents 9
• Corticosteroids must be used with caution if there is potential co-infection with Strongyloides due to risk of hyperinfection 1
• In approximately one-fourth of children with negative antibody results after therapy, symptoms of the disease may still persist 8
• Due to risk of ocular form, which may develop at any stage of the disease regardless of antibody concentrations, antiparasitic treatment is justified in all children infected with T. canis 8