SAPHO syndrome: a long-term follow-up study of 120 cases.

Objective: To assess the long-term outcome of the synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome.
Methods: All patients with the SAPHO syndrome seen at our unit between 1974 and 1997 were identified. Follow-up was prospective from 1992 to 1997. Data before 1992 were analyzed retrospectively. Clinical symptoms, treatments and biological data, including erythrocyte sedimentation rate and C-reactive protein, were recorded at least yearly. When available, radiological data, HLA B27 status, and findings from bone or skin biopsy specimens were recorded. For each drug, an efficacy index (El) was determined as follows: "0" for less than 30% improvement, as judged by the patient, on horizontal visual analog scale, "0.5" for partial efficacy, and "1" for more than 60% improvement.
Results: We identified 120 patients with the SAPHO syndrome (50 men, 70 women), of whom 102 patients were followed-up prospectively after 1992; 3 of these 102 patients were lost to follow-up. Six patients also had Crohn's disease, and three had ulcerative colitis. Except for a significant association of palmoplantar pustulosis (PPP) or psoriasis vulgaris (PV) with axial osteitis (P = .007), the dermatologic presentation had no significant influence on rheumatic symptoms (ie, osteitis or arthritis, peripheral or axial). The HLA B27 antigen was not significantly associated with a particular pattern of distribution of arthritis or osteitis. No severe or disabling complications were noted. In the 47 patients followed-up for more than 5 years (mean, 9.5; range, 5 to 23), the mean number of osteitis or arthritis foci increased during follow-up from 1.57 to 1.91 and from 2.68 to 3.11, respectively. Nonsteroidal antiinflammatory drugs (NSAIDs) were prescribed in 113 of 120 (94%) patients, with a mean El of 0.67 (+/-0.39). Corticosteroid (CS) therapy was used in 23 patients, with a mean El of 0.67 (+/-0.42). Colchicine and sulfasalazine had a mean El of 0.36 (+/-0.44) and 0.16 (+/-0.30), in 28 and 18 patients, respectively. Methotrexate was given to 10 patients (6 with peripheral arthritis), with a mean El of 0.64 (+/-0.48). Doxycyclin (100 mg twice daily) was used in 20 patients, usually to treat osteitis, with a mean El of 0.26 (+/-0.42). Intraarticular injections of a CS or osmic acid were used in 27 patients, with a mean El of 0.77 (+/-0.35).
Conclusions: SAPHO syndrome is a relevant and stable entity, with a good long-term prognosis. NSAIDs and intraarticular injections (CS or osmic acid) most often alleviate rheumatic symptoms, but prednisone or methotrexate are sometimes necessary and appear globally helpful.