acne fulminans or hidradenitis suppurativa. Pyoderma gangrenosum,
Sweet’s syndrome and other neutrophilic dermatoses can
also be seen. Osseous involvement can range from osteitis with
sclerosing features to hyperostosis with cortical thickening resulting
from chronic periostal reaction. Erosive arthritis can also
occur. Osteoarticular manifestations most commonly involve the
anterior chest wall, especially the sternocostoclavicular region,
but can also involve the spine, pelvic girdle, sacroiliac joints, peripheral
joints, long bones or mandibles. These osteoarticular
changes are best characterized by total body scintigraphy, but
plain radiographs, computed tomography and magnetic resonance
imaging studies can also be alternatives.
The pathogenesis of SAPHO syndrome remains poorly understood
but likely involves infectious, genetic and immunologic
mechanisms. A pathogenic role of Propionibacterium acnes (P.
acnes) causing a reactive osteitis in genetically predisposed individuals
has been proposed since the microbe has been isolated
from bone biopsy specimens. However, it remains unclear if the
osteoarticular changes seen in SAPHO syndrome are directly
related to P. acnes. Associations with inflammatory cytokine overproduction
and neutrophil dysfunction have also been reported.
SAPHO syndrome generally has a chronic and protracted
course; however, the severity of the symptoms can vary greatly
from person to person. Given the rarity of the disease and the
lack of large controlled studies, treatment remains empiric to
date. Non-steroidal anti-inflammatory agents and analgesics
generally provide only modest improvement. Bisphosphonates
can be used given their anti-inflammatory effects and their inhibition
of bone resorption and turnover. Antimicrobial agents
may be considered given the suspected role of P. acnes, but
their efficacy remains anecdotal. Recently, treatment with TNFalpha
inhibitors and interleukin-1 receptor antagonists has
shown promise for refractory cases.
None of the authors have disclosed a conflict of interest.
- Wendling, D et al. Anakinra treatment of SAPHO syndrome: short-term results of an open study. 2011.Ann Rheum Dis.
- Assmann, G, Simon P. The SAPHO syndrome - Are microbes involved? 2011.Best Practice & Research Clinical Rheumatology.
Abdelghani, et al. Tumor Necrosis Factor-alpha Blockers in SAPHO Syndrome. 2010. J Rheumatol. 37:1699-70
Roopal Kundu MDrkundu@nmff.org