Can a Single Local Corticosteroid Injection Cause Anemia?
No, a single local corticosteroid injection does not cause anemia in otherwise healthy adults. In fact, corticosteroids typically stimulate erythropoiesis (red blood cell production) rather than suppress it.
Evidence Supporting Erythropoietic Stimulation
Corticosteroids stimulate red blood cell production in normal bone marrow. Children with acute immune thrombocytopenic purpura demonstrated significant increases in hemoglobin and red blood cell counts during prednisone treatment, confirming that corticosteroid therapy enhances erythropoiesis in vivo 1.
Local injections have minimal systemic hematologic effects. While local glucocorticoid injections (epidural or intra-articular) do cause systemic absorption with effects lasting weeks, the documented complications include Cushing syndrome, bone density loss, hyperglycemia, and infection—but not anemia 2.
Systemic Absorption Does Not Equal Hematologic Suppression
Systemic absorption occurs but targets different systems. Three cortivazol injections (approximately 250 mg prednisone-equivalent total) caused corticotropic axis suppression, transient blood pressure elevation, and glucose elevations in diabetic patients, but no hematologic parameters were affected 3.
The documented side effects of local steroid injections do not include anemia. Complications from steroid injections are rare and primarily involve infection risk, hyperglycemia (especially in diabetics requiring close glucose monitoring for two weeks post-injection), and metabolic effects—not blood count suppression 4.
When Corticosteroids ARE Associated with Anemia
The only contexts where corticosteroids relate to anemia involve specific disease states or combination therapies, not the steroid itself:
Immunosuppressive combinations in transplant recipients. Anemia develops from azathioprine or mycophenolate mofetil (which are myelosuppressive), sirolimus (which interferes with erythropoietin signaling), or ACE inhibitors/ARBs—not from corticosteroids alone 5.
Pure red cell aplasia is an autoimmune phenomenon, not a steroid side effect. The case report describing CNS lupus during steroid therapy involved pre-existing PRCA from antiphospholipid syndrome, where steroids were the treatment, not the cause 6.
Clinical Bottom Line
A single local corticosteroid injection in a healthy adult will not cause anemia. If anemia develops after such an injection, investigate alternative causes including:
- Pre-existing hematologic conditions
- Concurrent medications (NSAIDs causing GI bleeding, other myelosuppressive agents)
- Underlying inflammatory or autoimmune disease
- Infection or malignancy
The physiologic effect of corticosteroids on erythropoiesis is stimulatory, not suppressive 1. Any anemia temporally associated with a steroid injection represents coincidence or an unrelated process requiring standard hematologic workup.