Tropical Pulmonary Eosinophilia

Excerpt

Tropical pulmonary eosinophilia is a hyperresponsive pulmonary syndrome in response to trapped microfilariae within the lung tissue. Tropical pulmonary eosinophilia, a term first described by Weingarten in 1943, is a clinical manifestation of lymphatic filariasis caused by filarial nematodes. It was previously described as "pseudotuberculosis with eosinophilia" by Frimodt-Moller in 1940.

Tropical pulmonary eosinophilia has a gradual onset, with primary symptoms including fever, nocturnal cough, dyspnea, and wheezing. While this condition is most common in filarial-endemic regions, its prevalence has recently increased in developed countries due to migration and globalization. Lymphatic filariasis, classified as a neglected tropical disease, predominantly manifests as elephantiasis. According to the World Health Organization (WHO), approximately 120 million people are affected by lymphatic filariasis in tropical and subtropical regions, but less than 1% develop tropical pulmonary eosinophilia.

Pulmonary eosinophilic syndromes can be classified as extrinsic or intrinsic based on causative factors. The extrinsic causes include medications (eg, sulfonamides, phenytoin, phenobarbital, and carbamazepine) and infectious agents (eg, parasites, fungi, mycobacteria). The intrinsic causes include Churg-Strauss syndrome, eosinophilic granuloma, chronic eosinophilic pneumonia, and idiopathic hypereosinophilic syndrome. Tropical pulmonary eosinophilia is classified as an extrinsic cause.