Bone loss in patients with SAPHO syndrome: a preliminary study

Synovitis, acne, palmoplantar pustulosis, hyperostosis and osteitis (SAPHO) syndrome is a rare entity that involves the skin, bones and joints. The estimated prevalence of SAPHO syndrome is lower than 1/10 000.1 The real prevalence may be underestimated because of lack of typical symptoms.2 Bone is one of the critical affected organs for SAPHO. The most common site is the anterior chest wall (65%–90%), followed by the thoracic spine.1 However, the effects of SAPHO syndrome on bone loss or osteoporosis have not been clarified. We performed a case–control study to show bone loss in patients with SAPHO syndrome in a Chinese population. From June 2014 to August 2019, a total of 27 new-onset SAPHO patients were included in the study after excluding patients who had been diagnosed for more than 6 months and who were younger than 25 years old. The diagnosis of SAPHO syndrome was based on clinical symptoms and radiological examinations.2 The diagnosis is based on the presence of at least one of four features: (1) osteoarticular manifestations with severe acne; (2) osteoarticular manifestations with palmoplantar pustulosis; (3) hyperostosis with or without skin lesions; (4) recurrent multifocal chronic osteomyelitis involving the axial or peripheral skeleton, with or without skin lesions. Two or three age-matched and gender-matched control subjects who underwent chest CT scan for physical examinations …