A Case of Syndrome of Progressive Muscle Spasm, Alopecia, and Diarrhea (Satoyoshi) Treated with Steroid Pulse Therapy

A 20-year-old man with Satoyoshi syndrome, characterized by progressive muscle spasms, alopecia, and diarrhea, was treated with steroid pulse therapy after other treatments failed. He experienced painful muscle cramps starting at age 12, which worsened over time and were accompanied by mild hair loss and diarrhea. Upon admission, he had mild baldness, a shoulder deformity, and hypertrophic muscles. Laboratory tests showed high serum CK and low IgG levels. Previous treatments with muscle relaxants and antiepileptic drugs were ineffective. The patient received high-dose intravenous methylprednisone followed by oral prednisolone, which led to a gradual decrease in muscle cramps and improved daily activity. The study concluded that steroid pulse therapy was effective for patients unresponsive to dantrolene sodium, suggesting an autoimmune mechanism in the disease's pathogenesis.