Etiology of Bursitis Bursitis may be caused by the following: Injury Chronic overuse and / or pressure Inflammatory arthritis (eg, gout, rheumatoid arthritis, psoriatic arthritis, spondylitis) Acute or chronic infection (eg, Staphylococcus aureus in acute infections and mycobacteria in chronic infections) Idiopathic and traumatic causes are by far the most common.