What is the treatment for coughing up worms, likely due to a parasitic infection such as paragonimiasis (lung fluke infection)?

Treatment for Coughing Up Worms (Paragonimiasis)

Treat with praziquantel 25 mg/kg three times daily after meals for 1-2 days, as this is the definitive treatment for paragonimiasis causing expectoration of lung flukes. 1, 2, 3, 4

Immediate Diagnostic Confirmation

Before initiating treatment, confirm the diagnosis through:

• Sputum microscopy to identify Paragonimus eggs or adult worms (gold standard) 1, 2
• Serologic testing via ELISA, available through specialized centers or CDC 1, 3, 5
• Peripheral blood eosinophilia (present in approximately 50% of cases) and elevated serum IgE 1
• Chest imaging showing pleural effusion, mass lesions, or infiltrates that may mimic tuberculosis 1, 3

Treatment Protocol

Primary Therapy

• Praziquantel 25 mg/kg body weight three times daily after meals for 1-2 days is the treatment of choice 1, 2, 3, 4
• This regimen achieves complete clinical and radiographic recovery 3
• Patients may expectorate adult worms during or after treatment 2

Adjunctive Considerations

• Corticosteroids may be considered (expert opinion) to prevent establishment of pulmonary fibrosis, particularly in severe cases 1
• Bronchodilators may help manage dyspnea if present 1
• Ongoing respiratory specialist follow-up is recommended for monitoring pulmonary complications 1

Theoretical Adjuncts

• Some experts suggest considering doxycycline and diethylcarbamazine (theoretical benefit), though this requires specialist consultation 1
• WARNING: Diethylcarbamazine requires careful evaluation for co-infection with onchocerciasis before use 1

Critical Differential Diagnosis

Paragonimiasis frequently mimics tuberculosis, presenting with:

• Chronic cough with sputum production and hemoptysis (often "chocolate-colored" and foul-smelling) 1
• Pleuritic chest pain and pleural effusion 1, 3
• Radiographic findings similar to TB 1, 3

Rule out tuberculosis in all cases, especially in:

• Patients from TB-endemic regions 1
• Recent Asian immigrants where both conditions may coexist 4
• Those with risk factors for TB (HIV, injection drug use, institutional exposure) 1

Epidemiologic Clues

Obtain detailed exposure history:

• Consumption of raw or undercooked freshwater crabs or crayfish is the primary transmission route 1, 5, 4
• Geographic exposure: Asia (P. westermani), Africa, Americas, or Mississippi River Basin in the United States (P. kellicotti) 1, 5, 4
• Ingestion of raw wild boar meat (paratenic host) is an alternative route 1
• In tropical regions, 10-15% of chronic cough cases may be paragonimiasis 1

Clinical Presentation Timeline

• Days to 3 weeks (early phase): Epigastric/abdominal pain, diarrhea, urticaria as parasites migrate 1
• Week 2 onwards (pulmonary phase): Cough with sputum, pleuritic chest pain, characteristic hemoptysis 1
• Chronic phase: Ongoing respiratory symptoms that may lead to pulmonary fibrosis if untreated 1

Common Pitfalls to Avoid

• Do not delay treatment while awaiting serologic confirmation if clinical suspicion is high and sputum shows eggs or worms 1, 2
• Do not misdiagnose as lung cancer in patients with mass lesions on imaging 1
• Monitor for relapses as they may occur after treatment 1
• Recognize that fever is rare in paragonimiasis, unlike many other parasitic infections 1