Tropical pulmonary eosinophilia.

Tropical pulmonary eosinophilia (TPE) usually affects people living in the tropics, especially those in Southeast Asia, India, and certain parts of China and Africa. However, owing to the rising frequency of world-wide travel and the migration between continents, this disease is increasingly seen in the West, where the diagnosis can be easily missed since it is rarely encountered and can mimic many other conditions. Cases of TPE have typically been reported to masquerade as acute or refractory bronchial asthma. TPE results from a hypersensitivity reaction to lymphatic filarial parasites found in endemic regions. There is evidence that it is more likely to occur in nonimmune individuals, ie, visitors to endemic regions, than in individuals of endemic populations who have developed immunity to filarial infections. Clinical features include paroxysmal cough, wheezing and dyspnea, and systemic manifestations such as fever and weight loss. A history of residence in a filarial endemic region and a finding of peripheral eosinophilia >3,000/mm3 should initiate a consideration of this disease. Other criteria for the diagnosis of TPE include absence of microfilariae in the blood, high titers of antifilarial antibodies, raised serum total IgE >1,000 U/mL, and a favorable response to the antifilarial, diethylcarbamazine, which is the recommended treatment. This disease, if left untreated or treated late, may lead to long-term sequelae of pulmonary fibrosis or chronic bronchitis with chronic respiratory failure. Herein lies the importance of early diagnosis and treatment of TPE.