Scleromyxedema (SM) is a rare disorder which initially presents with waxy skin stiffness and maculopapular lesions. It also has non-dermatologic manifestations, such as serum paraproteinemia and myopathies, and is sometimes associated with other autoimmune disorders. A 52-year-old man was referred for treatment because of torso-dominant skin stiffness. He also had a neglected history of bilateral inflammatory back pain and chronic Helicobacter pylori-negative gastritis. Skin histopathology confirmed a diagnosis of SM. A grade 4 bilateral sacroilitis and a positive human leukocyte antigen B27 led to the patient also being diagnosed with ankylosing spondylitis (AS). Upon further analysis, monoclonal gammopathy of immunoglobulin (Ig) G/kappa (lower than 3 g/dl) and a normal percentage of plasma cells in his bone marrow aspiration sample were discovered. Due to the patient’s IgA deficiency, intravenous immunoglobulin (IVIG) could not be used to treat his SM; due to his positive tuberculin skin test (25 mm) and history of gastritis, anti-tumor necrosis factor alpha and non-steroid anti-inflammatory drugs were also withheld. The patient received a drug regimen of cyclosporine (3mg/kg/day) and high-dose prednisolone (0.5mg/kg/day) which successfully controlled both his SM and AS disorders. In this paper, we report a previously unreported case of SM-associated gammopathy and AS. We also show the efficacy of cyclosporine and high-dose prednisolone in the treatment of both of these conditions.