TROPICAL PULMONARY EOSINOPHILIA: NOCTURNAL SYMPTOMS

Dear Editor,

This 24 year old serving soldier presented with dry cough, breathlessness, mild grade fever and generalised bodyaches for the last 15 days. On examination he was moderately built, temperature – 37.8°C, Pulse-90/min regular, BP – 110/70 mm of Hg and throat was normal. Chest did not reveal any wheeze or crackles. Abdomen/CVS/CNS/ – Normal. Next morning patient complained that he was unable to sleep because of dry cough and breathlessness through out the night Chest did not reveal any wheeze or crackles. Systemic examination was again normal.

On next day patient had similar complaints and was not able to sleep through out the night Again clinical examination did not reveal any abnormal finding. On subsequent night, patient was examined: chest had extensive bilateral wheeze mainly in infrascapular and interscaplar areas. Bronchodilators were given and investigated further. Haemogram: Hb. 14.0 gm/dl, TLC-8000 per cmm with 18% eosinophils on differential count Absolute eosinophil count was 1440 per cmm. Blood slide for MF was negative (twice) during night. Urine examination, chest radiograph and electrocardiogramm were normal.

Clinical diagnosis of Tropical Pulmonary Eosinophilia was considered. Diethylcarbamazine was started in low doses, gradually increased over three days to full doses and continued for 14 days. Patient responded well and became asymptomatic within a week, though absolute eosinophil count became normal on 10th day.

Tropical Pulmonary Eosinophilia is a distinct syndrome which is thought to be an allergic reaction to dead microfilaria in the lungs, perhaps a species for which man is an unusual host such asDirofilaria immitis or Brugia phangi [1] (normally affecting animals accidentally conveyed to man by mosquitoes). This syndrome affects commonly young male, often during the third decade of life. The majority of cases have been reported from India, Pakistan, Srilanka and South East Asia.

Symptoms are usually nocturnal (diurnal variation) in the form of cough, dyspnea, asthmatic paroxysms with fever for weeks to months and pronounced eosinophilia. Among 12 to 25% of individuals there is a tendency to relapse over a period of few years [2]. Microfilarial parasites in the blood are usually absent. There is a rise in all immunoglobulins particularly lgE and antifilarial antibody titres which are characteristically high [3]. Chest X-ray may be normal but generally shows increased bronchovascular marking; diffuse bilateral, indefinite mottling of varying size (2–5mm in diameter) uniformly distributed in both the lungs [2].

There is usually dramatic relief of symptoms with Diethylcarbamazine (antifilarial drug) within 3 to 7 days, though eosinophilia may take 7 to 10 days or sometimes longer to become normal. Treatment is to be continued for 10 to 14 days or till eosinophil count becomes normal. Sometimes after an interrval of years, individuals with relapse require another course of diethylcarbamazine [4].

The typical clinical features include dry cough and wheeze which are solely nocturnal, high eosinophilia very high levels of antifilarial antibodies and a rapid initial response to tratment with diethylcarbamazine are virtually diagnostic of Tropical Pulmonary Eosinophilia (TPE).