Adult-onset Satoyoshi Syndrome with Prominent Laterality of Clinical Features

We herein report the case of a patient with adult-onset Satoyoshi syndrome. Alopecia was detected on the patient's head, left leg and abdomen, with pigmentation on the left thigh and abdomen. Painful muscle spasms were also noted in the abdomen and left upper and lower extremities, and a sensory disturbance was present in the left thigh. A skin biopsy of this field showed lymphocyte infiltration, and the patient was found to be positive for antinuclear antibodies and rheumatoid factor. These clinical findings were atypical, as they were lateralized. This case is the first report of Satoyoshi syndrome associated with a sensory disturbance. The patient's histological findings and positivity for autoantibodies indicated the presence of immunological abnormalities in this case of Satoyoshi syndrome.