Tropical Pulmonary Eosinophilia

Tropical pulmonary eosinophilia (TPE) is a hyperresponsive pulmonary syndrome in response to trapped microfilariae within the lung tissue. TPE is a clinical manifestation of lymphatic filariasis caused by filarial nematodes. Weingarten first described the term tropical pulmonary eosinophilia (TPE) in 1943. It was previously described as “pseudotuberculosis with eosinophilia.” The onset of tropical pulmonary eosinophilia is slow, and the major symptoms are fever, nocturnal cough, dyspnea, and wheezing. TPE is common in the filarial endemic region, but recently an increase in the prevalence of this disease is seen in developed countries due to migration and globalization. Lymphatic filariasis is a neglected tropical disease, and the most common clinical manifestation of this disease is elephantiasis. According to the World Health Organization (WHO), an estimated 120 million people are infected with lymphatic filariasis in tropical and subtropical regions. Study shows that less than 1% of individuals with filariasis will develop TPE. Pulmonary eosinophilic syndromes can be classified as extrinsic or intrinsic on the basis of causative factors. The extrinsic causes include medications (sulfonamides, phenytoin, phenobarbital, and carbamazepine) and infectious agents (parasites, fungi, mycobacteria). The intrinsic causes include Churg-Strauss syndrome, eosinophilic granuloma, chronic eosinophilic pneumonia, and idiopathic hypereosinophilic syndrome. Tropical pulmonary eosinophilia comes under extrinsic causes.