The foul odour is due to mixed flora of bacteria consisting of Pseudomonas, Proteus. E coli, anaerobic streptococci and bacteroids. The Chronic osteitis provides the right environment for the growth of these bacteria.
Discharge is scanty, continuous, purulent, foul smelling and often blood stained and has no association with URTI.
The discharge is episodic, copious, mucopurulent, odourless and not blood stained. Discharge increases with episodes of URTI.