Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome may present with extra-articular and cutaneous manifestationsSAPHO syndrome is a rare autoinflammatory disease that manifests with articular and cutaneous symptoms. Although epidemiological data on SAPHO are limited, the annual incidence of the disease is estimated to be 1 in 10 000 in Caucasians and 0.00144 in 10 000 in Japanese. 1 The precise pathogenesis of SAPHO syndrome remains elusive, but it is hypothesized to have a genetic basis, linked to underlying infections and immune dysfunction.SAPHO syndrome is commonly recognized as a distinct pathological condition by researchers. However, some researchers have suggested that SAPHO syndrome can be classified as a form of spondyloarthritis, a potential transitional stage between ankylosing spondylitis (AS) and psoriatic arthritis. 2,3 Both SAPHO syndrome and spinal arthritis affect the axial and sacroiliac joints in a similar manner, exhibiting shared characteristics and even instances of co-occurrence. 4,5 SAPHO syndrome may be associated with the HLA-B27 gene. 2 Patients with AS have multisystemic damage such as the heart, lungs, kidneys, eyes, intestines, skin, and bones through the support of a large number of data. 6Common extra-articular manifestations in AS include uveitis, inflammatory bowel disease, and psoriasis. These symptoms are also found in SAPHO syndrome in addition to the articular and cutaneous manifestations.