2015 Volume 25 Issue 3 Pages 273-278
The characteristic symptoms of tuberculous otitis media (TOM) are refractory otorrhea and hearing loss. However, these symptoms are nonspecific manifestations with respect to other diseases such as nonspecific chronic otitis media, cholesteatoma. Therefore, the diagnosis of TOM is not simple, and is typically delayed. But, an early diagnosis and treatment of TOM can prevent complications such as facial paralysis or irreversible hearing loss.
The diagnosis of TOM is made if a specimen from the middle ear reveals the presence of acid fast bacilli, grows Mycobacterium tuberculosis (M.Tb) on a culture, and/or is positive for polymerase chain reaction for M.Tb. However false-negative reactions can occur with these tuberculin tests. Until recently, the tuberculin skin test was the only test for detecting latent tuberculosis infection. In response, Interferon-Gamma Release Assays (IGRAs) have been developed. 2 tests are included in IGRAs, one is the QuantiFERON (QFT)-TB-2G and the other test is the T-SPOT.TB. The tuberculin skin test uses a relatively crude mix of antigen from M.Tb, so false-positive reactions or false-negative reactions can occur with tuberculin tests. But both IGRAs use more specific M.Tb antigens - ESAT-6 and CFP-10. Therefore, the specificity of IGRAs is higher than the tuberculin skin test. Of course, IGRAs cannot distinguish an active infection from a latent infection. However, if the result of IGRAs is positive, we can perform tests for M.Tb promptly.
