Treatment for Lung Fluke (Paragonimiasis)
Praziquantel is the definitive treatment for paragonimiasis, with the standard regimen being 25 mg/kg three times daily for 2 days. 1, 2, 3
First-Line Treatment Regimen
- Praziquantel 25 mg/kg orally three times daily for 2 consecutive days is the treatment of choice for all Paragonimus species infections 1, 2, 3, 4, 5
- This regimen achieves cure in the vast majority of cases and is well-tolerated 2, 3
- Treatment should be initiated promptly once diagnosis is confirmed to prevent pulmonary fibrosis and potential CNS complications 1, 2
Adjunctive Therapies to Consider
- Corticosteroids may be beneficial in preventing the establishment of pulmonary fibrosis, though this is based on expert opinion rather than controlled trials 1
- Bronchodilators can be used for symptomatic relief of dyspnea if present 1
- Ongoing respiratory physician follow-up is recommended for patients with significant pulmonary involvement 1
Alternative Regimens (When Praziquantel Unavailable)
The 2025 UK guidelines mention theoretical benefit of alternative agents, though these are not standard:
- Doxycycline and diethylcarbamazine (DEC) have theoretical benefit but require expert consultation before use 1
- Critical warning: DEC should never be used without first ruling out onchocerciasis co-infection through skin snips and slit lamp examination, as it can cause severe reactions including blindness in co-infected patients 1
Monitoring for Treatment Response
- Repeat sputum microscopy or bronchoalveolar lavage to document clearance of ova 1, 4
- Clinical improvement should include resolution of cough, hemoptysis, and chest pain 1, 3
- Chest imaging follow-up to assess resolution of pulmonary lesions 1, 6
- Serum IgE levels and eosinophil counts typically normalize with successful treatment 1
Important Clinical Pitfalls
- Do not mistake paragonimiasis for tuberculosis: Both present with chronic cough, hemoptysis, and chest radiograph abnormalities, but paragonimiasis requires specific antiparasitic therapy 1, 2, 4
- Eosinophilia is present in only approximately 50% of cases, so its absence does not exclude the diagnosis 1
- The characteristic "chocolate" or foul-smelling hemoptysis, when present, is highly suggestive of paragonimiasis 1
- Relapses may occur after treatment, necessitating clinical follow-up 1
When to Seek Expert Consultation
- CNS involvement (cerebral paragonimiasis) requires specialist input for potential surgical intervention 2
- Consideration of alternative agents (doxycycline/DEC) mandates tropical medicine or parasitology consultation 1
- Severe pulmonary disease with extensive fibrosis may benefit from multidisciplinary management including respiratory specialists 1