Scanty, foul smelling painless discharge from the ear is characteristic feature of which of the following lesions:

(b) Cholesteatoma(Ref. Cummings, 6th ed., 2141)In cholesteatoma the ear discharge is due to bone erosion, hence it is scanty and foul smelling. It is painless.In central perforation, i.e. safe CSOM the ear discharge is painless, on and off and is mucopurulent, non-foul smelling and moderate in amount.In ASOM following rupture of TM, there is relief of pain and the ear discharge is profuse, mucopurulent and non-foul smelling.In Otitis externa, e.g. furuncle, the ear discharge is only purulent and characteristically lacks the mucoid component which indicates that it is not coming from the middle ear. It is associated with pain.