Bursitis is an inflammation or degeneration of the sac-like structures that form in utero to protect the soft tissues from underlying bony prominences . Septic bursitis refers to inflammation of the bursa that is due to infection, typically resulting from bacterial inoculation that is either direct (eg, puncture wound), spread from nearby soft tissues (eg, cellulitis), or hematogenous (eg, bacterial endocarditis). Much less commonly, mycobacteria, fungi, or algae are the causative agents.
Nonseptic bursitis due to trauma, repetitive injury, crystal diseases, and other systemic disorders is discussed separately. (See "Bursitis: An overview of clinical manifestations, diagnosis, and management".)
ETIOLOGY AND PATHOGENESIS
There are more than 150 bursae in the human body. Bursae may be divided by location into those that are superficial or deep. Superficial bursae are subcutaneous and separate skin from deeper tissues such as periosteum or ligaments. Deep bursae serve to reduce friction between fibrous structures such as tendons from adjacent bone. Bursae are lined by synovial cells, which under ordinary circumstances produce a small amount of lubricating fluid.
Superficial bursae — The superficial or subcutaneous bursae are predisposed to infection as a result of skin trauma. Direct inoculation due to puncture of the overlying skin, or contiguous spread from cellulitis are presumed to be the most common mechanisms involved in septic superficial bursitis [2,3]. The majority of reported cases have been in men [4-7]. Trauma to the skin and bursa may be occupational, due to recreational activities, or related to concomitant diseases. Among these the following are notable [2,8-10]:
●Olecranon septic bursitis — Due to repetitive trauma in plumbers, carpenters, miners, athletes, patients with chronic obstructive pulmonary disease (possibly the result of leaning on the elbows) and those receiving chronic hemodialysis via vascular access in the arm.