Case reports: aseptic femoral osteitis and sternocostal hyperostosis from SAPHO syndrome

Long-term clinical course of two rare cases of synovitis-acne-pustulosis-hyperostosis-osteomyelitis syndrome involving only unilateral femur

Synovitis-acne-pustulosis-hyperostosis-osteomyelitis (SAPHO) syndrome is characterised by aseptic osteitis and is often complicated by pustular dermatitis, such as palmoplantar pustulosis or acne. Although bone lesions are most found in the anterior thoracic region or spine, femoral lesions are not well documented in the literature. There is no established treatment for this condition, and few reports have described its long-term course. Here, we describe two cases of SAPHO syndrome involving the femur and discuss their long-term follow-up. A 40-year-old man (Case 1) presented with right thigh pain. Fifteen years after the initial diagnosis, the pain could be controlled with minomycin, salazosulfapyridine, and methotrexate. X-rays of the femur showed gradual cortical thickening. Although there were waves of pain, it gradually improved with the adjustment of drugs 25 years following the initial diagnosis. A 35-year-old man (Case 2) with right thigh pain was prescribed salazosulfapyridine and methotrexate; however, these were ineffective. Alendronate and guselkumab also proved ineffective. Ultimately, infliximab was started 9 years following disease onset, and pain became manageable. X-rays of the femur showed cortical thickening. SAPHO syndrome can be managed with drug therapies, such as nonsteroidal anti-inflammatory drugs, methotrexate, and conventional synthetic disease-modifying antirheumatic drugs; however, there are occasional treatment-resistant cases.

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome of femoral neoplasm-like onset: a case-based review

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is an umbrella term covering a constellation of bone lesions and skin manifestations, but has rarely been clarified in the clinic. We report a 28-year-old woman who had initial onset of SAPHO syndrome with involvement of the femur, and she experienced a tortuous diagnostic course. We also performed a literature review of SAPHO syndrome cases involving the femur and summarize several empirical conclusions by integrating previous findings with our case. Furthermore, we propose our perspective that ailment of the skin caused by infection of pathogens might be the first hit for triggering or perpetuating the activation of the immune system. As a result, musculoskeletal manifestations are probably the second hit by crosstalk of an autoimmune reaction. The skin manifestations preceding bone lesions can be well explained. Current interventions for SAPHO syndrome remain controversial, but drugs aiming at symptom relief could serve as the first preference for treatment. An accurate diagnosis and appropriate treatment can cure patients in a timely manner. Although the pathogenesis of SAPHO syndrome remains to be determined, physicians and surgeons still need to heighten awareness of this entity to avoid invasive procedures, such as frequent biopsies or nonessential ostectomy.

Synovitis, Acne, Pustulosis, Hyperostosis, and Osteitis Syndrome with Purely Osteolytic, Not Osteosclerotic, Lesions Mimicking a Malignant Tumor

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is a rare inflammatory disorder with multiple phenotypes. The syndrome has identifiable radiologic characteristics that are the most important when making a diagnosis. X-rays of cases diagnosed with SAPHO syndrome reveal sclerotic lesions or mixed lytic and sclerotic lesions. Pure osteolytic lesions in SAPHO syndrome are rare, and to the best of our knowledge, no study has reported the radiologic change of purely osteolytic lesions to osteosclerotic lesions over time. Herein, we report on the case of a woman experiencing severe left thigh acute pain and having a medical history of palmoplantar pustulosis. Although SAPHO syndrome was suspected because of palmoplantar pustulosis, based on radiologic findings, bone metastasis of a malignant tumor or chronic bacterial osteomyelitis owing to a purely osteolytic lesion was suspected. However, needle biopsy revealed no malignancy and bacterial culture was negative, thus suggesting SAPHO syndrome. Nonsteroidal anti-inflammatory drugs, bisphosphonates, and corticosteroids were administered, which improved the left thigh pain. Furthermore, the radiologic change of osteolytic lesions to osteosclerotic lesions over time was confirmed, leading to the diagnosis of SAPHO syndrome. Our case demonstrates that knowledge of atypical radiologic findings is necessary to diagnose initial SAPHO syndrome.

The SAPHO syndrome--are microbes involved?

The syndrome of synovitis, acne, pustulosis, hyperostosis and osteitis (SAPHO) includes a rare group of chronic, relapsing, inflammatory osteoarticular disorders that is conventionally associated with manifestations in the skin. Diagnostic dilemmas can arise due to incomplete manifestations or confusion generated through mimicking of other conditions, such as osteomyelitis. The aetiology of this syndrome remains unclear, but probably involves genetic, immunological and infectious mechanisms. The possible pathogenetic role of infectious agents in genetically predisposed individuals, resulting in a 'reactive osteitis', has been suggested because microbes such as Propionibacterium acnes have been recovered from bone biopsy samples. However, this hypothesis has not been demonstrated as yet. Current knowledge with regard to treatment of this syndrome is based on results reported from small case studies and, thus, is still empiric. The use of antibiotics, instituted based on the isolation of Propionibacterium acnes, has been reported to show conflicting results. Promising results for potential future application have recently been reported for treatment of SAPHO with bisphosphonates and antagonists of tumour necrosis factor-α. This review aims to evaluate the existing knowledge on the SAPHO syndrome and to provide information on symptoms, diagnosis and treatment options for this disease.

SAPHO Syndrome Diagnosis and Treatment: Report of Five Cases and Review of the Literature

Background:

The term “SAPHO (Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis) syndrome” includes a variety of musculoskeletal disorders associated with skin conditions; Osteitis is the most prominent skeletal lesion, whereas palmoplantar pustulosis and acne are the main skin lesions. Diagnosing SAPHO syndrome is difficult, because this syndrome is often confused with suppurative osteomyelitis, which has similar clinical and pathologic findings. SAPHO diagnosis is even more difficult when atypical sites are involved and there are no skin lesions.

Patients and Methods:

This case series presents five patients (3 women, 2 men), ages 27 to 44 years, who came to the Orthopaedic Department outpatient clinic for evaluation of pain in the humerus, clavicle, sacroiliac joints, and/or distal radius, and were diagnosed with SAPHO syndrome. Clinical and radiologic findings, treatment and outcome data, with up to 4 years of follow-up are presented. An extensive discussion of the clinical presentation, published literature, treatment options and outcome of SAPHO syndrome is also included.

Results:

Once the diagnosis of SAPHO syndrome was established, treatment with antibiotics (clindamycin) and non steroid anti-inflammatory drugs (lornoxicam) was remarkably effective. All patients did well and remained symptom free for up to four years, after a 3-8 month course of treatment.

Interpretation:

SAPHO syndrome should be included in the differential diagnosis when evaluating patients with lytic, sclerotic, or hyperostotic bone lesions and pain. Prompt SAPHO syndrome recognition, followed by appropriate therapy with antibiotics and NSAIDs can produce rapid symptom resolution, while avoiding unnecessary procedures and longterm antibiotic therapy.

Femoral and lower costosternal junctions' osteitis in an adult with SAPHO syndrome: An unusual presentation

The combination of synovitis, acne, pustulosis, hyperostosis and aseptic osteitis is known as SAPHO syndrome. Osteitis involves the anterior chest, particularly the sternoclavicular and upper costosternal junctions. Diagnosis is difficult when there are no typical skin and bone lesions and differential diagnosis includes bacterial ostomyelitis, malignancy and Paget's disease. We present a case of SAPHO syndrome with aseptic femoral osteitis and symmetrical involvement of the lower costosternal junctions. The main advantage of recognition and diagnosis of SAPHO syndrome is the avoidance of unnecessary prolonged antibiotic treatment and repeated invasive procedures.