Coexistence of systemic sclerosis and ankylosing spondylitis: A case report and literature review.

Systemic sclerosis (SSc) is an autoimmune disease characterized by thickening of the skin and organ fibrosis. Ankylosing spondylitis (AS) is a type of arthritis with long-term inflammation of the axial joints. Previous studies presented 5 cases of concomitant AS and SSc. However, there was only 1 patient of those 5 cases complaining of muscle weakness while all patients had approximately normal creatine kinase (CK). Here we reported a young male who met the criteria for SSc and AS while showing significantly elevated CK. Human leukocyte antigen (HLA) typing results indicated the genetic susceptibility to these two diseases. The patient was prescribed prednisone (30 mg/d) and cyclophosphamide. After 2 months, the patient's skin became soft with normal CK.