[SAPHO syndrome]

The SAPHO syndrome, an acronym for synovitis, acne, pustulosis, hyperostosis and osteitis, is a rare disease which affects bones, joints and the skin. The main osteoarticular features are hyperostosis and osteitis. Osteoarticular symptoms predominantly occur on the anterior chest wall but the spine and the peripheral skeleton can also be involved. The most important skin affections are palmoplantar pustulosis and severe acne. The etiology of this syndrome remains unclear but infectious, immunological and genetic factors are involved. The diagnostic features of SAPHO syndrome are clinical and radiological. The most important diagnostic procedure is Tc-99 m bone scintigraphy but conventional x-rays as well as computed tomography (CT) and magnetic resonance imaging (MRI) can also contribute to the final diagnosis. Bone histology and positron emission tomography CT (PET-CT) may help to differentiate SAPHO syndrome from malignancies and infectious osteomyelitis. Nonsteroidal anti-inflammatory drugs (NSAIDs) are the cornerstone of treatment. The results obtained using antibiotics and disease-modifying antirheumatic drugs (DMARDs), such as sulfasalazine and methotrexate are inconsistent. Bisphosphonates and anti-tumor necrosis factor (anti-TNF) drugs have shown promising results in small studies but further research is still necessary.