Sapho (Synovitis, Acne, Pustulosis, Hyperostosis, Osteitis) Syndrome
Last updated: November 25, 2014
ICD9 Code: Chronic osteomyelitis 730.10
ICD10 Code: Chronic multifocal osteomyelitis, unspecified M86.30
Synonyms: Palmoplantar pustulosis, sternocostoclavicular hyperostosis, pustulotic arthrosteitis, chronic recurrent multifocal osteomyelitis, acne arthritis or acne-associated SpA, and hidradenitis suppurativa–associated arthritis.
Definition: SAPHO syndrome comprises a variety of disorders manifesting reactive osteitis, arthritis, and chronic cutaneous pustular lesions.
Etiology: The cause is unknown. SAPHO syndrome is often considered to be reactive owing to pustulosis, osteitis, and clinical similarities with the SpA.
Pathology: Hyperostotic bony lesions, osteitis, and inflammatory synovitis are seen.
Demographics: This very rare disorder affects males and females equally. Most cases are reported in Japan. Far fewer cases are seen in whites, predominantly from Scandinavia and France. Most frequently it affects adults between
20 and 60 years of age.
Cardinal Findings: Painful, nodular swelling of skeletal lesions characterized by development of early erosive and late hyperostotic changes in the joints of the anterior chest wall or axial skeleton. Skeletal disease develops after established pustulosis (i.e., palmoplantar pustulosis, acne conglobata, acne fulminans, hidradenitis suppurativa, pustular psoriasis). The anterior chest wall and axial skeleton are preferentially targeted. Affected amphiarthroses (saddle joints) of the anterior chest wall include the sternoclavicular, manubriosternal, and sternocostal joints. Peripheral involvement of the hands and feet is uncommon. Spondylodiscitis and enthesitis are sometimes seen. Chronic relapsing pustular lesions may affect palms or soles (palmoplantar pustulosis), intertriginous areas (hidradenitis), or face, trunk, and extremities (acne).
Diagnostic Tests: Mild to moderate elevation of the acute-phase reactants and increased leukocyte counts are common. Serum RF is usually absent, and HLA-B27 is positive in <30% of patients.
Differential Diagnosis: Other SpA, DISH, fluorosis, retinoid therapy, ochronosis, alcaptonuria, and hypoparathyroidism should be considered.
Imaging: Early in the disease, radiographs show erosive changes in the anterior chest wall joints, sometimes accompanied by subchondral sclerosis and periostitis. With chronicity, subchondral sclerosis and hyperostosis ensue. Bony ankylosis is uncommon. Spondylodiscitis is the most common axial finding and is suggested by erosions of the vertebral plates with reactive vertebral sclerosis. Sacroiliitis is seen in as many as one-third of patients. Bone scans reveal increased uptake in affected skeletal areas.
Therapy: Topical and systemic therapies are directed at the underlying pustular disorder. The musculoskeletal manifestations are often difficult to treat, although most individuals exhibit some response to systemic antibiotics, NSAIDs, and oral or intraarticular corticosteroids. Sulfasalazine and colchicine have been suggested but not tested extensively. Recent use of parenteral pamidronate or TNF inhibitors appears promising.
Surgery: Resection of the proximal clavicular head or synovectomy may be necessary to control pain.
BIBLIOGRAPHY
Cush JJ, Lipsky PE. Reiter’s syndrome and reactive arthritis: hyperostotic syndromes associated with cutaneous pustular lesions. In: Koopman WJ, ed. Arthritis and allied conditions: a textbook of rheumatology, 13th ed. Baltimore: Williams & Wilkins,1997:1222–1223.
Kahn MF, Chamot AM. SAPHO syndrome. Rheum Dis Clin North Am 1992;18:225–246.PMID:1532859
