In a prospective study conducted in four villages of North Arcot Ambedkar district of Tamil Nadu in south India over a 5 yr period from 1981-86, 279 patients were detected to have
pulmonary tuberculosis (PTB). Thirty one of them were found to have associated
hypereosinophilia (HE) with total blood eosinophil level of > or = 2000 per cumm; besides
cough with expectoration they also complained of dyspnoea and wheeze. Twelve of the 18 patients with intestinal parasites had remission with deworming agents alone. The other 6 non responsive patients like the 13 who did not have parasitic infestation, needed treatment with
diethylcarbamazine for eosinopenic remission and thus could be classified as patients of tropical
pulmonary eosinophilia (TPE). The association of hypereosinopilic state as a whole as well as TPE with
tuberculosis as compared to that prevalent in the general population was found to be highly significant (P < 0.001). The frequent association of TPE with
tuberculosis as observed by us suggests the possibility of an early
hypersensitivity reaction to mycobacterial
antigens triggering a florid TPE state in susceptible patients from an area endemic for
filariasis. A similar mechanism may also operate in cases of
pulmonary eosinophilia induced by other helminths in areas where they are endemic.