SAPHO syndrome in which certolizumab pegol was effective: A case report

Abstract

A 45-year-old male suffered from persistent swelling and redness, with pain in his left lower leg and ankle. Pathological findings isolated from the ankle joint by arthroscopic synovectomy showed mild synovitis. Initially, this case was diagnosed as chronic mild arthritis and later treated as phlegmon because of the persistent redness and swelling inflammatory findings in his left lower leg. A systemic survey was performed. Based on the findings—such as chronic ankle arthritis with ipsilateral plantar pustulosis, chronic recurrent multifocal osteomyelitis in left distal tibia with MRI, calcaneal osteitis with computed tomography, and pathological findings that neither malignant tumor nor infection was detected—this case reached the definitive diagnosis of SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome. The hot spots detected in the bilateral sternoclavicular and costosternal joints with bone scintigraphy and their arthritic change detected by computed tomography also supported the diagnosis of SAPHO syndrome. This case was refractory to NSAIDS; therefore, the TNF inhibitor certolizumab pegol was tried. This agent rapidly improved not only the chief complaints but also the objective symptoms and laboratory findings at most six weeks after its administration.