B83.0 Visceral larva migrans

Name of the Condition

• Visceral larva migrans

Summary

Visceral larva migrans is a parasitic infection caused by the larval stages of certain nematodes, primarily Toxocara canis or Toxocara cati, which migrate through visceral organs. The condition typically affects individuals who have ingested eggs from contaminated soil, resulting in larval migration through tissues such as the liver, lungs, or central nervous system. Clinical manifestations vary depending on the organs involved and the intensity of infection.

Causes

The infection is caused by the larval forms of Toxocara species, which are common parasites in dogs and cats. Humans become infected through accidental ingestion of embryonated eggs present in soil, sand, or other contaminated environments. The larvae hatch in the intestine, penetrate the intestinal wall, and migrate to various organs, where they can cause inflammatory responses and tissue damage.

Risk Factors

• Exposure to soil or sand contaminated with animal feces, particularly in areas with poor sanitation.
• Contact with pets (especially puppies or kittens) that may carry Toxocara eggs.
• Pica (ingestion of non-food items) in children, increasing the risk of egg ingestion.
• Residing in or traveling to regions with high rates of animal fecal contamination.
• Immunocompromised states that may alter the body's response to larval migration.

Symptoms

• Fever, fatigue, or general malaise.
• Abdominal pain, nausea, or vomiting.
• Cough, wheezing, or respiratory distress if larvae affect the lungs.
• Hepatomegaly (enlarged liver) or splenomegaly (enlarged spleen).
• Neurological symptoms, such as seizures or behavioral changes, in severe cases.
• Eosinophilia (elevated eosinophil count) in blood tests.

Diagnosis

Diagnosis is based on clinical presentation, exposure history, and laboratory findings. Serological tests for Toxocara antibodies are commonly used to confirm infection. Imaging studies (e.g., ultrasound, CT, or MRI) may be performed to assess organ involvement, particularly in cases with suspected visceral or neurological involvement. A complete blood count (CBC) may reveal eosinophilia, supporting the diagnosis.

Treatment Options

Treatment typically involves anthelmintic medications, such as albendazole or mebendazole, to target the migrating larvae. Corticosteroids may be used to reduce inflammation in severe cases, especially when the central nervous system or eyes are involved. Supportive care, including management of symptoms like fever or respiratory distress, is also important. The duration of treatment depends on the severity of infection and organ involvement.

Prognosis and Follow-Up

Prognosis is generally favorable with appropriate treatment, though outcomes depend on the extent of organ involvement and the patient's overall health. Most individuals recover without long-term complications, but severe cases (e.g., involving the brain or eyes) may require ongoing monitoring. Follow-up appointments may include repeat serological testing or imaging to assess resolution of symptoms and organ function.

Complications

• Organ damage, such as liver or lung injury, due to larval migration.
• Neurological complications, including encephalitis or seizures, in rare cases.
• Ocular larva migrans, which can lead to vision impairment or blindness.
• Persistent eosinophilia or allergic reactions in some individuals.

Lifestyle & Prevention

• Practice good hand hygiene, especially after contact with soil or pets.
• Avoid ingesting soil or sand, particularly in areas with known animal fecal contamination.
• Regularly deworm pets and maintain clean living environments to reduce egg exposure.
• Supervise young children to prevent pica and ensure safe play areas.
• Wear gloves when gardening or handling soil in endemic regions.

When to Seek Professional Help

Seek medical attention if you experience unexplained fever, respiratory symptoms, abdominal pain, or neurological changes after potential exposure to contaminated soil or pets. Prompt evaluation is important for individuals with suspected visceral larva migrans, especially if symptoms worsen or persist.

Tips for Medical Coders

When coding for visceral larva migrans (B83.0), ensure documentation supports the diagnosis, including clinical findings, exposure history, and laboratory or imaging results. Note the specific Toxocara species if identified, as this may influence coding specificity. Verify that the code aligns with the patient's documented condition and that all relevant details (e.g., organ involvement, treatment) are captured to support accurate coding and billing.