The SAPHO syndrome: a single-center study of 41 adult patients.

Objective: The SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis, osteitis) is a rare disease and only a few series have been published about it. We describe the experience of a rheumatology department with a focus on the therapeutic aspects.
Methods: All cases of SAPHO fulfilling the Benhamou criteria and seen between 1992 and 2013 in our unit were retrospectively included.
Results: Forty-one patients (11 men and 30 women) were included. The average age was 45 years (20-80 yrs) at the time of diagnosis. Nineteen patients had palmoplantar pustulosis, 3 had psoriasis vulgaris, 3 had severe acne, and 15 had no dermatological involvement. Bone symptoms involved mainly the anterior chest wall (n = 28, 68%), followed by the spine (n = 16, 39%) and sacroiliac joints (n = 12, 29%). Four patients had peripheral osteitis and 2 had mandibular osteitis. Ten patients had peripheral arthritis affecting mainly the knees and wrists. None of the 36 patients tested was HLA-B27-positive. At least a partial response was achieved with colchicine, methotrexate, or sulfasalazine in 0/6, 2/4, and 1/6 of patients, respectively. Antibiotic therapy (azithromycin, n = 7; doxycycline, n = 2) was effective in 2/9 patients. Pamidronate was prescribed in 26 patients with bone involvement and 18/22 patients evaluable at 6 months responded to this therapy. Two patients were treated with tumor necrosis factor blockers: 1 with infliximab and 1 with adalimumab, followed by etanercept.
Conclusion: Based on our experience, SAPHO can be diagnosed in the elderly. It was not associated with HLA-B27. Soft tissue involvement was common and the bisphosphonates were generally effective on bone involvement.