Patient with thin painless otorrhoea, multiple perforations of the tympanic membrane and failure to respond to antimicrobial treatment. What is the most probable causative organism -

Ans. is 'a' i.e., Mycobacterium tuberculosiso Thin painless otorrhoea, multiple perforations of the tympanic membrane and failure to respond to antimicrobial treatment are the features of tubercular otitis media and it is caused by Mycobacterium tuberculosis.Tubercular otitis mediao Tuberculosis of middle ear is a comparatively rare entity usually seen in association with or secondary to pulmonary tuberculosis, infection reaches the middle ear through eustachian tube.o The rare modes of infection are through hematogenous spread from tubercular focus in lung, tonsils, cervical lymph nodes; or due to ingestion of infected cow's milk,o It usually affects children and young adults.Clinical featureso Generally, tuberculosis of middle ear is unilateral.o It is characterized by painless otorrhoea which fails to respond to the usual antimicrobial treatment. There is painless watery otorrhea.o Single or multiple perforation of tympanic membrane. There may be multiple perforations in the early stages, but they coalesce into a large tympanic membrane perforation accompanied by a pale granulation tissue.o Periauricular fistulae, lymphadenopathy and facial palsy are infrequent findings.o Late complications include facial paralysis, labyrinthitis, postauricular fistulae, subperiosteal abscess, petrous apicitis and intracranial extension of infection