Chronic Nonbacterial Osteomyelitis, Hidradenitis Suppurativa, and SAPHO Syndrome

Introduction: Synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome may represent one side of a spectrum of disease that also includes chronic nonbacterial osteomyelitis. Case: A 23-year-old male with bone pain in the anterior chest, shoulder, clavicles, left elbow, and left ankle presented to rheumatology clinic after multiple evaluations for infectious osteomyelitis. Imaging and deep bone biopsies of affected areas were consistent with chronic osteomyelitis, with labs notable for elevated erythrocyte sedimentation rate, C-reactive protein, and positivity for HLA-B27. A full skin exam was consistent with hidradenitis suppurativa, and he was started on infliximab and methotrexate with improvement in both his osteoarticular and skin symptoms.   Conclusions: Patients presenting with features of follicular occlusion or neutrophilic dermatoses in conjunction with bone pain should be evaluated for SAPHO/CNO. In patients with SAPHO/CNO with vertebral involvement, bisphosphonates in addition to anti-inflammatory medications (such as methotrexate and TNF-inhibitors) can be effective.