SAPHO （Synovitis, Acne, Pustulosis, Hyperostosis, and Osteitis Syndrome） syndrome is a systemic disease consisting of unexplained pustular skin lesions and osteoarthritic lesions, and was reported by Chamot et al. in 1987. The present study reports a rare case of SAPHO syndrome in an adult male. A 42-year-old male outpatient came to the Department of Oral and Maxillofacial Surgery for a consultation with the chief complaint of persistent pain following extraction of the first premolar on the right side of the lower jaw. Computed tomography （CT） showed diffuse osteosclerosis with indistinct boundaries in the premolar region on the right side of the lower jaw. According to the results of MRI, a low signal area in this region was observed on T1-weighted images, while a high signal area was observed on T2-weighted images. Tc̄99 scintigraphy revealed an increased accumulation in the right lower jaw, bilateral sternoclavicular joints, and finger/toe joints. The patient had a history of palmoplantar pustulosis and chest/joint pain. Blood tests indicated normal values for rheumatoid factors, anti-CCP antibodies, and antinuclear antibodies, whereas an increasing tendency in leukocytes and CRP levels was detected. SAPHO syndrome was strongly suspected, hence macrolide antibiotics （Clarith®） and NSAIDs were prescribed, resulting in improvement of the patient.
