Question

Tropical pulmonary eosinophilia.

Hint:

Early diagnosis and treatment with DEC are essential for managing TPE. Corticosteroids may be added in severe cases to control inflammation.

Answer 1

Step 1: Introduction to Tropical Pulmonary Eosinophilia (TPE).
Tropical pulmonary eosinophilia (TPE) is a parasitic lung disease caused by Wuchereria bancrofti or Brugia malayi, which are filarial worms transmitted through the bite of infected mosquitoes. TPE is characterized by eosinophilic inflammation in the lungs and is typically seen in individuals living in tropical regions where lymphatic filariasis is endemic. It primarily affects adults, but children can also be affected. Step 2: Clinical Features of Tropical Pulmonary Eosinophilia.
- Cough (often persistent and dry), wheezing, and dyspnea (shortness of breath) are common symptoms.
- Fever is often present, and patients may report night sweats or fatigue.
- Chest tightness and pain may occur due to lung inflammation.
- Eosinophilia in the peripheral blood is characteristic, with marked increase in eosinophils (often >3000 cells/mm³).
- Pulmonary infiltrates may be seen on imaging, and these are typically patchy or bilateral with a subpleural distribution.
Step 3: Diagnosis of Tropical Pulmonary Eosinophilia.
(1) Clinical suspicion: A history of residence in an endemic area and symptoms like persistent cough, dyspnea, and eosinophilia in the blood may raise suspicion.
(2) Peripheral blood eosinophilia: A hallmark feature of TPE is a marked increase in eosinophils. This can be confirmed by routine blood tests.
(3) Immunodiagnostic tests: Detection of IgG4 antibodies specific to filarial antigens or circulating filarial antigens in the blood confirms infection with filarial worms.
(4) Chest X-ray: May show bilateral infiltrates with peripheral distribution, indicative of eosinophilic inflammation.
(5) Lung biopsy: Rarely required, but histopathological examination may reveal eosinophilic granulomas and filarial microfilariae.
(6) Ultrasound or PCR: These may help in identifying microfilariae or confirming filarial infection.
Step 4: Treatment of Tropical Pulmonary Eosinophilia.
(1) Antifilarial Therapy: - The mainstay of treatment for TPE is the use of diethylcarbamazine (DEC), which is effective against the filarial worms. DEC is given for 12-21 days, typically in doses of 6 mg/kg/day.
- If DEC is not available or tolerated, ivermectin or albendazole may also be used as alternative treatments.
- Corticosteroids may be used to manage severe eosinophilic inflammation and lung injury (e.g., prednisolone 20-40 mg daily for a few weeks).
(2) Symptomatic Treatment: - Bronchodilators like beta-agonists (e.g., salbutamol) and antihistamines can help relieve wheezing and cough.
- Oxygen therapy may be necessary in severe cases with significant respiratory compromise.
- Antipyretics like paracetamol can help manage fever and general malaise.