Complications of Injecting a Subacromial Bursa Complications are uncommon and include Subcutaneous fat atrophy, skin atrophy and sinus tracts, and temporary skin depigmentation due to inadvertent subcutaneous corticosteroid injection Painful local reaction thought to result from a chemical synovitis in response to the crystals in the corticosteroid solution (sometimes called a postinjection flare) occurring within a few hours of depot corticosteroid injection and usually lasting ≤ 48 hours Infection In diabetic patients, hyperglycemia after a depot corticosteroid injection Tendon, nerve, or blood vessel damage from misdirected corticosteroid injection due to errant needle insertion Equipment for Injecting a Subacromial Bursa Antiseptic solution (eg, chlorhexidine, povidone iodine, isopropyl alcohol) Sterile gauze, gloves, sterile adhesive bandage Needle insertion site anesthesia (eg, topical freezing spray and / or injectable 1% lidocaine without epinephrine, in a 3-mL syringe) Optional: For therapeutic injection, 1% lidocaine (without epinephrine) mixed with injectable depot corticosteroid (eg, triamcinolone acetonide, 20 to 40 mg) Hemostat, if switching of syringe while the needle remains inserted is anticipated 27-gauge, 1.5-inch needle (for injection, not aspiration) Some 3 -, 5 -, and 10-mL syringes Having an assistant is helpful.