The association between delayed type hypersensitivity reaction to Mycobacterium tuberculosis and atopy in asthmatic children

Background: It has been postulated that there is an inverse association between mycobacterium tuberculosis infection and atopy. We aimed to investigate if there is a similar relation in our study group, consisting 252 asthmatic children. Methods: In tuberculin testing indurations greater than or equal to 5 mm were accepted as positive. The most common aeroallergens were used in skin prick testing and reactions 3 mm were accepted as positive. Results: In 139 patients PPD was negative, where as in 113 patients PPD was positive. Among the PPD (-) patients skin prick test was positive in 64 % (n = 89). Among the PPD (+) patients skin prick test was positive in 71 % (n = 80). As the two groups were compared for having positive skin prick test reactions no statistically significant difference was detected between them (p = 0.283). Conclusions: Tuberculin reactivity is not inversely associated with atopy in asthmatic children.