Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome - A challenging diagnosis not to be missed

Stellate ganglion block in the treatment of SAPHO syndrome: A case report

Synovitis, acne, palmoplantar pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is a rare and refractory autoinflammatory disease, and there is no consensus on its treatment. Stellate ganglion block (SGB) blocks sympathetic nerves, ameliorates immune dysfunction, and alleviates stress response, which has been used to treat various chronic pain syndromes, arrhythmias, and post-traumatic stress disorder (PTSD). Also, the SGB has been reported to be successfully used to treat certain skin diseases, autoinflammatory diseases, and menopausal symptoms. In this study, over 3 years of follow-up, we found that SGB successfully intervened the symptoms of SAPHO syndrome, including sternoclavicular joint arthritis and palmoplantar pustulosis.

The challenging diagnosis of synovitis-acne-pustulosis-hyperostosis-osteitis (SAPHO) syndrome: A rare case report

Considered rare, the synovitis-acne-pustulosis-hyperostosis-osteitis (SAPHO) syndrome is a distinct clinical entity, associating skin manifestations and osteoarticular symptoms. Anterior chest wall pain centered at sternoclavicular and sternocostal joints is an important and characteristic clinical finding that can lead to its diagnosis. Radiologists and clinicians must be aware of synovitis-acne-pustulosis-hyperostosis-osteitis syndrome as it can mimic some of the more common disease entities such as Paget's disease. We report the case of a 63-year-old male patient, with no significant medical history, who presented to the dermatology department, with severe palmar and plantar pustulosis associated with polyarthralgia. Computerized tomography scan showed sternoclavicular hyperostosis, in favor of SAPHO syndrome, with regression of clinical symptoms after non-steroidal anti-inflammatory drug treatment.

Psoriasis, bone and bowel: a comprehensive review and new insights

Psoriasis is a chronic immune-mediated disorder affecting about 2% of the population worldwide which is associated with significant morbidity. The disease usually presents as raised, well-demarcated erythematous plaques with adherent silvery scales. Psoriasis can appear at any age but it has two peaks occurring at 15–20 and 55–60 years of age. It affects males and females equally. Despite the multitude of investigations about psoriasis and even development of drugs with satisfactory results, its pathogenesis is not fully understood yet and its course is unpredictable. Various environmental triggers, e.g., obesity, stress and drugs may induce disease in genetically susceptible patients. Although psoriasis was considered primarily as a disease of the skin, more investigations have been revealed its systemic nature. Psoriatic arthritis (PsA) may complicate up to one-third of cases of psoriasis vulgaris (PV). Also, the association between psoriasis and a variety of other immune-mediated disorders such as inflammatory bowel disease (IBD) and celiac disease (CD) has been confirmed in various studies. Moreover, a growing body of evidences indicates that psoriasis shares some common histological and phenotypical properties with the spectrum of osteoimmunological diseases such as Paget’s disease of bone (PDB). Thus, exploring the common molecular and genetic mechanisms underlying psoriasis and related disorders is of paramount importance for better elucidating disease pathogenesis and designing more targeted treatments.

SAPHO syndrome complicated with relapsing polychondritis: A case report

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is a rare chronic inflammatory disease. The main clinical manifestation of SAPHO syndrome is an osteoarthropathy with cutaneous involvement. Relapsing polychondritis (RP) characterized by chronic inflammation and cartilage degeneration is a rare systematic autoimmune disease. Here we report a RP case in a SAPHO syndrome patient, in which auricularitis happened 10 years after the diagnosed as SAPHO syndrome. Tofacitinib treatment can alleviate the symptoms.

Clinical spectrum of Cutibacterium acnes infections: The SAPHO syndrome

Cutibacterium acnes, previously known as Proprionobacterium, is a commensal Grampositive bacterium of the skin commonly implicated in prosthetic joint infections. However, it has been documented to play a role in other conditions, including SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis, osteitis), a rare autoinflammatory disorder. Diagnosing SAPHO syndrome is cumbersome, as the clinical manifestations are variable and overlap with many inflammatory joint disorders. Herein, we describe a 56-year-old female patient with a presumed diagnosis of longstanding seronegative rheumatoid arthritis and history of C. acnes prosthetic joint infection following revision arthroplasty of the right shoulder. She presented to our clinic with a rash over the upper extremities and trunk and joint symptoms involving the right shoulder. Treatment was initiated with ceftriaxone followed by doxycycline suppressive therapy, with clinical improvement of joint and skin involvement. Symptoms recurred upon brief cessation of antibiotic therapy due to adverse gastrointestinal effects; however, symptoms abated once again upon re-initiation of treatment. Given the patient's cutaneous lesions and longstanding history of arthritis that improved with antimicrobial therapy against C. acnes, the diagnosis of SAPHO syndrome was entertained. The present case demonstrates the clinical challenges of diagnosing SAPHO syndrome and the importance of its consideration on the differential for a patient with osteoarticular and cutaneous features. Additional literature is needed to improve diagnostic criteria and treatment guidelines.

Synovitis, acne, pustulosis, hyperostosis, osteitis syndrome with invisible organizing pneumonia: A case report

We report the case of a 59-year-old female patient, presenting with pustular rash on both hands and pain in the lumbosacral part and left lower limb. A magnetic resonance imaging examination of the left leg was undertaken and the result showed that a malignant lesion with bone destruction of the left femoral shaft could not be excluded. Subsequently, bone tumor was excluded by pathological examination. Lung computed tomography scan showed patchy consolidation and cord shadow in the middle left lung. Subsequently, lung cancer was excluded by pathological examination, and the histopathological changes of lung were consistent with those of organized pneumonia. Blood tests revealed elevated C-reactive protein and erythrocyte sedimentation rate. Antinuclear antibody, rheumatoid factor, and human leukocyte antigen-B27 were unremarkable. Whole body bone scintigraphy via technetium 99m-methyl diphosphonate showed increased radionuclide uptake in the left middle femur. Based on her clinical manifestations, imaging results and bone scintigraphy, the patient was diagnosed as having synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome. Loxoprofen and Tripterygium wilfordii Hook F led to impressive clinical and radiologic improvement.

Pro and contra: is synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) a spondyloarthritis variant?

PURPOSE OF REVIEW

The purpose of this review is to present the up-to-date evidence on the epidemiology, pathogenesis, musculoskeletal manifestations, and imaging of the synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome and to discuss its relationship with spondyloarthritis (SpA).

RECENT FINDINGS

SAPHO is a rare inflammatory disorder of bone, joints, and skin, with a worldwide distribution that predominantly affects the middle-age adults. The hallmark of the syndrome is a constellation of sterile inflammatory osteitis, hyperostosis, and synovitis involving the anterior chest wall, associated with acneiform and neutrophilic dermatoses, such as palmoplantar pustulosis and severe acne. The axial skeleton, sacroiliac, and peripheral joints can be involved in a similar fashion to SpA. The pathogenesis of the syndrome is multifactorial. The diagnosis is mainly based on the clinical and typical radiological features. The treatment approach is based on the off-label use of antibiotics, bisphosphonates, disease-modifying antirheumatic drugs, and anticytokine biologics.

SUMMARY

The SAPHO syndrome shares common features with SpA-related diseases, yet also shows some unique pathogenetic and clinical features. The nosology of SAPHO remains a subject of controversy, awaiting further research into the pathogenetic and clinical aspects of this syndrome. A better understanding of these aspects will improve the diagnostics and clinical care of patients with SAPHO.

A case of SAPHO syndrome: a DISH of radiological features to be considered

Background

The acronym SAPHO stands for synovitis, acne, pustulosis, hyperostosis, and osteitis. It is a rare heterogenous disease with unknown etiology and a chronic relapsing and remitting course¹. Its skin and osteoarticular manifestations including palmoplantar pustulosis (PPP) and synovitis may be transient which further complicate the diagnosis. So, awareness about all features of the syndrome throughout the time seems mandatory for correct diagnosis and avoidance of unnecessary procedures.

Case presentation.

A case of SAPHO syndrome being reported in a middle-aged man who presented with bilateral PPP and exacerbation of back pain which developed shortly after covid-19 vaccine injection with a history of more than 20 years of inflammatory thoracic back pain and psoriasis vulgaris who initially had been worked up for metastatic bony lesions based on radiologic studies, irrespective of his skin lesions. The patient had good response to alendronate 70 mg weekly and celecoxib 200 mg BID without aggravation of existing skin lesions or new psoriatic lesions.

Conclusion

This case report aims to inform rheumatologists and radiologists about various radiologic and dermatologic manifestations of SAPHO syndrome with emphasizing on taking into consideration of past and present skin lesions in the interpretation of the radiologic signs in order to prevent irrelevant procedures or hazardous imaging and to urge rheumatology societies to set up a SAPHO registry for future randomized controlled trials. Suggestion of PPP responsiveness to NSAIDs as a new potential diagnostic tool for SAPHO diagnosis is another goal. It also aims to point out the possible coexistence of SAPHO and SpA or DISH syndrome.

SAPHO Syndrome: An Unusual Cause of Dysphagia

CASE PRESENTATION

This case describes a 51-year-old male who presented to the emergency department with a complaint of two weeks of progressively worsening dysphagia as well as the emergence of superficial fluid collections on the anterior chest and leg during the same period. Computed tomography showed retropharyngeal and paratracheal fluid collections with adjacent vertebral osteitis; however, biopsies were negative for any infectious or mycobacterial source, and instead showed chronic inflammatory changes.

DISCUSSION

Synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome is a rare rheumatic disorder that presents with multifocal osteitis and sterile neutrophilia. SAPHO syndrome may be easily mistaken for a diffuse infectious process on initial evaluation and imaging; however, it is treated with anti-inflammatory medications, including non-steroidal anti-inflammatory drugs and corticosteroids. Although most patients achieve remission of symptoms with treatment, the location of the fluid collections and resultant bony destruction may be life-threatening if undiagnosed.

The combined prevalence of classified rare rheumatic diseases is almost double that of ankylosing spondylitis

BACKGROUND

Rare diseases (RDs) affect less than 5/10,000 people in Europe and fewer than 200,000 individuals in the United States. In rheumatology, RDs are heterogeneous and lack systemic classification. Clinical courses involve a variety of diverse symptoms, and patients may be misdiagnosed and not receive appropriate treatment. The objective of this study was to identify and classify some of the most important RDs in rheumatology. We also attempted to determine their combined prevalence to more precisely define this area of rheumatology and increase awareness of RDs in healthcare systems. We conducted a comprehensive literature search and analyzed each disease for the specified criteria, such as clinical symptoms, treatment regimens, prognoses, and point prevalences. If no epidemiological data were available, we estimated the prevalence as 1/1,000,000. The total point prevalence for all RDs in rheumatology was estimated as the sum of the individually determined prevalences.

RESULTS

A total of 76 syndromes and diseases were identified, including vasculitis/vasculopathy (n = 15), arthritis/arthropathy (n = 11), autoinflammatory syndromes (n = 11), myositis (n = 9), bone disorders (n = 11), connective tissue diseases (n = 8), overgrowth syndromes (n = 3), and others (n = 8). Out of the 76 diseases, 61 (80%) are classified as chronic, with a remitting-relapsing course in 27 cases (35%) upon adequate treatment. Another 34 (45%) diseases were predominantly progressive and difficult to control. Corticosteroids are a therapeutic option in 49 (64%) syndromes. Mortality is variable and could not be determined precisely. Epidemiological studies and prevalence data were available for 33 syndromes and diseases. For an additional eight diseases, only incidence data were accessible. The summed prevalence of all RDs was 28.8/10,000.

CONCLUSIONS

RDs in rheumatology are frequently chronic, progressive, and present variable symptoms. Treatment options are often restricted to corticosteroids, presumably because of the scarcity of randomized controlled trials. The estimated combined prevalence is significant and almost double that of ankylosing spondylitis (18/10,000). Thus, healthcare systems should assign RDs similar importance as any other common disease in rheumatology.

Sternoclavicular Septic Arthritis Caused by Cutibacterium acnes in a Previously Healthy 13-Year-Old Male: A Case Report

CASE

A 13-year-old boy presented with 3 weeks of atraumatic left-sided sternoclavicular (SC) joint pain, swelling, and decreased range of motion. After imaging and laboratory workup, he underwent operative irrigation, debridement, and antibiotic therapy with complete resolution of his symptoms. Surgical cultures were consistent with SC septic arthritis.

CONCLUSION

The management of septic arthritis in pediatric patients remains varied. Here, we present the only report of SC septic arthritis due to Cutibacterium acnes in a healthy pediatric patient. Given the similar clinical findings of pain and swelling to affected bones and joints, differentiating SC septic arthritis from other conditions within the clinical spectrum of chronic nonbacterial osteomyelitis remains challenging. Clinicians should maintain a high index of suspicion when patients present with pain and swelling over the SC joint.

Chronic Nonbacterial Osteomyelitis of the Sternocostoclavicular Region in Adults: A Single-Center Dutch Cohort Study

Sternocostoclavicular hyperostosis (SCCH) is a rare autoinflammatory bone disorder caused by chronic nonbacterial osteomyelitis (CNO), which is associated with sclerosis and hyperostosis primarily affecting the sternum, the medial end of the clavicles, and the first ribs. Other areas of the axial skeleton may also be affected. The more severe synovitis–acne–pustulosis–hyperostosis–osteitis (SAPHO) syndrome is additionally associated with dermatoses and joint manifestations. This Dutch retrospective cross‐sectional single‐center cohort study characterizes the spectrum of clinical features in adult CNO/SCCH patients at the time of diagnosis. The only inclusion criteria was the availability of complete sets of clinical and imaging data systematically collected over three decades using in‐house protocols. Data from 213 predominantly female patients (88%) with a median age of 36 years at presentation were studied. The mean diagnostic delay was 5 ± 5 years. The main symptoms were chronic pain (92%), bony swelling (61%), and restricted shoulder girdle function (46%); 32% had palmoplantar pustulosis and 22% had autoimmune disease. The majority (73%) had isolated SCCH; 59 (27%) had additional localizations in vertebrae (19%), the mandible (9%), or both (2%); 4 had SAPHO. The prevalence of current or past smoking was high (58%), particularly for patients with palmoplantar pustulosis (76%). There was a significant relationship between delay in diagnosis and both the extent of affected skeletal sites (p = 0.036) and erythrocyte sedimentation rate levels (p = 0.023). Adult‐onset CNO is characterized by distinctive clinical and radiological features, but diverse aspects of its spectrum are currently not fully captured by a comprehensive classification. Delayed diagnosis is still common and potentially associated with irreversible structural changes and debilitating chronic symptoms, increasing the burden of illness and negatively impacting on quality of life. It is hoped that findings from this study will dispel confusion about nomenclature and classification of adult‐onset CNO and increase awareness of its distinctive clinical and radiological features, and thus facilitate early diagnosis and referral for treatment, which should positively impact prognosis by preventing disease progression, although this remains to be established. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Serum Sp17 Autoantibody Serves as a Potential Specific Biomarker in Patients with SAPHO Syndrome

SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome shows a wide variability in musculoskeletal and cutaneous manifestations, and it is therefore underrecognized and misdiagnosed in the clinic due to a lack of specific markers. In this study, we aimed to identify specific biomarkers by screening serum autoantibodies in SAPHO patients with a 17K human whole-proteome microarray. The serum anti-Sp17 autoantibody was identified and verified to be a specific biomarker in patients with SAPHO syndrome. Indeed, the level of the anti-Sp17 autoantibody was significantly increased in patients with active SAPHO compared to patients with an inactive disease and healthy controls (P < 0.05). Additionally, serum anti-Sp17 autoantibody levels correlated with those of serum hypersensitive C-reactive protein (hsCRP), the erythrocyte sedimentation rate (ESR), and β-crosslaps (β-CTx) in patients with active SAPHO disease. Moreover, anti-Sp17 autoantibody levels were markedly decreased after anti-inflammatory treatment with pamidronate disodium, which downregulated levels of hsCRP and ESR in patients with active SAPHO. Thus, serum levels of the anti-Sp17 autoantibody might serve as a specific biomarker for the diagnosis of SAPHO syndrome or for monitoring the disease status.

Tripterygium wilfordii Hook F. in the treatment of synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome: a clinical trial

OBJECTIVE

This study aimed to investigate the efficacy and safety of Tripterygium wilfordii Hook F. (TwHF) in the treatment of osteoarticular lesions in synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome.

METHODS

Eligible SAPHO patients were recruited to this single-center trial to receive 12-week TwHF treatment. Two dose groups (1.0-mg/kg/day group and 1.5-mg/kg/day group) were designed and patients were allocated (1:1) to these two groups. The primary endpoint was the change from baseline in Ankylosing Spondylitis Disease Activity Score on the basis of C-reactive protein level (ASDAS) at week 12.

RESULTS

All the 30 included patients completed the trial. At week 12, both dose groups showed significant change from baseline in ASDAS (1.0-mg/kg/day group: - 1.34 (1.10), p = 0.000; 1.5-mg/kg/day group: - 1.53 (1.19), p = 0.000). Similar improvement was also found in the Visual Analogue Scale in global osteoarticular pain, Bath Ankylosing Spondylitis Disease Activity Index, and other efficacy measures. The results showed a fast-acting characteristic of TwHF that the maximum efficacy was achieved within the first 2-4 weeks and maintained at a stable level for the rest of the study. No significant differences were observed between the two dose groups under the current sample size. TwHF was well tolerated that no severe adverse events or irregular menstruation were recorded, except for one patient who developed severe alanine aminotransferase elevation at the last follow-up and has stopped the TwHF treatment after the 12-week follow-up.

CONCLUSIONS

TwHF should be considered for the treatment of osteoarticular lesions in SAPHO syndrome in clinical practice because of significant efficacy, reliable safety, and high socioeconomic value.

TRIAL REGISTRATION

ChiCTR1900025912 Key points • This is the first clinical trial to evaluate Tripterygium wilfordii Hook F. (TwHF) in the treatment of synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome. • Twelve-week TwHF treatment in both dose groups designed (1.0-mg/kg/day group and 1.5-mg/kg/day group) was well tolerated and could lead to significant disease remission of SAPHO syndrome. • No significant differences were observed between the two dose groups under the current sample size. • TwHF should be considered for the treatment of osteoarticular lesions in SAPHO syndrome in clinical practice because of significant efficacy, reliable safety, and high socioeconomic value.

SAPHO syndrome: the supposed trigger by isotretinoin, the efficacy of adalimumab and the specter of depressive disorder: a case report

Background

SAPHO (synovitis, acne, pustolosis, hyperostosis and osteitis) syndrome is a rare autoinflammatory chronic disorder, presenting with non-infectious osteitis, sterile joint inflammation and skin manifestations including palmoplantar pustolosis and severe acne.

It could be often misdiagnosed for its heterogeneous clinical presentation. Treatment is challenging and, due to the rarity of this syndrome, no randomized controlled clinical trials have been conducted. Empirical treatments, including non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, antibiotics and bisphosphonates and disease-modifying anti-rheumatic drugs (DMARDs) could be quite effective. Anti-tumor necrosis factor-alpha (anti-TNF-α) agents and interleukin-1 (IL-1) antagonists have shown promising results in refractory patients. Isotretinoin, commonly used for severe acne, has been rarely described as possible trigger of osteo-articular manifestations, in particular sacroiliitis.

Case presentation

The case of a boy, affected by acne fulminans and depression, who presented with sacroiliitis after a 10-week treatment with isotretinoin is presented. After SAPHO diagnosis, NSAIDs therapy was started but the onset of bilateral gluteal hidradenitis suppurativa required the switch to a TNF-α antagonist (Adalimumab) with the achievement of a good control of the disease. Despite specific therapy with sertraline, the patient continued to complains severe depression.

Conclusions

Our case reports a temporal association between the onset of osteo-articular symptoms and the introduction of isotretinoin, as previously described. However, this timeline is not sufficient to establish a causal role of this drug into the pathogenesis of sacroiliitis. At this regard, further studies are required. The occurrence of hidradenitis suppurativa during SAPHO course supported the introduction of TNF-α blockers with a favourable result, as reported in a few cases in literature. The association between SAPHO syndrome and depressive mood disorders is already reported. Our patient experienced severe depression whose trend seems to be independent from the course of the main disease. Currently, it is not clarified if depression could be considered reactive to the underling disease or if it forms an integral part of the autoinflammatory disorder.

Mandibular involvement in SAPHO syndrome: a retrospective study

BACKGROUND

Mandible osteomyelitis can occur in synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome, a rare chronic inflammatory disease; however, few studies have explored its characteristics and management.

METHODS

We reviewed the medical records of consecutive SAPHO patients with mandible involvement diagnosed in Peking Union Medical College Hospital from September 2014 to July 2019. Demographic, clinical, laboratory, and imaging data were collected at baseline. Prescription data and follow-up magnetic resonance imaging (MRI) and cone beam computed tomography (CBCT) images were collected from the hospital information system. An electronic questionnaire was distributed to all patients to obtain their latest symptoms.

RESULTS

A total of 26 SAPHO patients with mandibular involvement were involved, all of whom responded to the questionnaire (38.5% male; median age, 28 years; median follow-up duration, 2.1 years). Ten patients (38.5%) had undergone an oral procedure 1 month before the onset of mandibular symptoms. All 14 of the patients who underwent a surgical intervention relapsed within a median duration of 2 months (range 0.25-4.0 months), and 24 patients (92.3%) achieved improvement with conservative treatment. Following bisphosphonate treatment, remission of bone marrow oedema and osteolysis was observed on MRI and CBCT, and 5 patients receiving bisphosphonates with follow-up CBCT after remission did not relapse in 5.4 months (mean 6.0, range 3.2-9.9 months).

CONCLUSION

Mandibular involvement of SAPHO syndrome predominantly occurs in young women. Dental procedures are a possible risk factor. Conservative treatment, especially intravenous bisphosphonates, can lead to oral improvement.

Acne in the first three decades of life: An update of a disorder with profound implications for all decades of life

Acne vulgaris is a chronic, inflammatory, skin condition that involves the pilosebaceous follicles and is influenced by a variety of factors including genetics, androgen-stimulation of sebaceous glands with abnormal keratinization, colonization with Cutibacterium acnes (previously called Propionibacterium acnes), and pathological immune response to inflammation. Acne can occur at all ages and this discussion focuses on the first three decades of life. Conditions that are part of the differential diagnosis and/or are co-morbid with acne vulgaris are also considered. Acne in the first year of life includes neonatal acne (acne neonatorum) that presents in the first four weeks of life and infantile acne that usually presents between 3 and 6 months of the first year of life with a range of 3 to 16 months after birth. Acne rosacea is a chronic, inflammatory, skin condition that is distinct from acne vulgaris, typically presents in adults, and has four main types: erythemato-telangiectatic, papulopustular, phymatous and ocular. Treatment options for acne vulgaris include topical retinoids, topical benzoyl peroxide, antibiotics (topical, oral), oral contraceptive pills, isotretinoin, and others. Management must consider the increasing impact of antibiotic resistance in the 21st century. Psychological impact of acne can be quite severe and treatment of acne includes awareness of the potential emotional toll this disease may bring to the person with acne as well as assiduous attention to known side effects of various anti-acne medications (topical and systemic). Efforts should be directed at preventing acne-caused scars and depigmentation on the skin as well as emotional scars within the person suffering from acne.

[Chronic nonbacterial osteomyelitis : Imaging and differential diagnoses]

Chronic nonbacterial osteomyelitis (CNO) is an autoinflammatory bone disease in childhood and adolescence with a preference for the female gender. It is manifested with multiple osseous lesions, with a predilection for the metaphyseal end zones of the long bones of the lower extremities. These bone lesions usually occur multifocally, can recur and develop a different appearance depending on the bone structure affected. Patients present with a longer disease history, changing clinical symptoms and unspecific paraclinical signs. Magnetic resonance imaging (MRI) is the imaging of choice and particularly as a whole body examination can speed up the diagnosis and is an important component of follow-up controls. Differential diagnoses include numerous inflammatory, benign and malignant bone diseases. Therefore, it is essential to know the diagnosis of CNO and to take it into consideration in cases of an unclear inflammatory bone process in young patients.

Radiographic changes of chronic recurrent multifocal osteomyelitis that persisted into adulthood

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare non-infectious autoinflammatory disorder typically seen in young women. We describe the case of a young man who presented at 13 years of age with pain in the tibia, humerus, clavicle and hip. Worsening of the condition through clinical presentation and radiographic imaging was observed over 10 years. Radiographic imaging initially showed some sclerotic changes, but worsened to osteolytic lesions of the proximal tibia, elevation of the lateral cortex and thickening of the anterior cortex. Bone biopsy of his right anterior proximal tibia showed no infection or neoplasia. But, laboratory results showed elevation of inflammatory markers such as erythrocyte sedimentation rate or C-reactive protein. The patient was diagnosed with CRMO and treated with antibiotics for suspicion of chronic bacterial osteomyelitis. Chronic bone pain, abnormal imaging and elevation of inflammatory markers suggesting that chronic bacterial osteomyelitis can lead to difficulties with the diagnosis of CRMO.

A patient with chronic sacroiliitis undiagnosed for three years after isotretinoin use

Background

Isotretinoin (ISO) is a synthetic vitamin A derivative which has been used for treatment-resistant acne vulgaris. Although most musculoskeletal side effects of ISO are common, including myalgia, arthralgia, and back pain, sacroiliitis is one of the uncommon side effects. ISO-induced sacroiliitis usually completely resolves within a few months by the cessation of the drug.

Case presentation

In this paper, we present a 26-year-old female patient with chronic sacroiliitis that was probably induced by ISO and not resolved by the discontinuation of the drug.

Conclusion

In this patient, sacroiliitis was overlooked for three years. Therefore, ISO usage should be considered in the differential diagnosis of sacroiliitis and low back pain.

SAPHO syndrome: A radiological case report

The SAPHO syndrome (synovitis–acne–pustulosis–hyperostosis–osteitis syndrome) is a rare chronic inflammatory disease of unknown etiology. Herein, we present a case of incidentally detected SAPHO syndrome in a middle-aged male patient who visited the hospital for pulmonary complaints.

Enhanced migration and adhesion of peripheral blood neutrophils from SAPHO patients revealed by RNA-Seq

Background

SAPHO syndrome is a rare disease characterized by inflammatory lesions on skin and bones. Diversified manifestation and inadequate understanding of etiology has limited its diagnosis and treatment. The co-occurrence of other immune-mediated diseases strongly suggests an involvement of autoimmunity in SAPHO syndrome. However, the role of the largest population of circulating immune cells, neutrophils, is still not well explored. In this study, we performed RNA sequencing to profile the mRNA expression of neutrophils purified from peripheral blood of SAPHO patients to identify key genes associated with SAPHO syndrome, trying to find new functional molecules or biomarkers for this rare disease.

Results

A total of 442 differentially expressed genes were identified (p < 0.05, fold change > 2), in which 294 genes were upregulated and 148 genes were downregulated. Five differentially expressed genes of interest were verified by quantitative Real-Time Polymerase Chain Reaction (qRT-PCR), among which S100A12 was upregulated and positively related to high-sensitivity C-reactive protein (hsCRP), while the downregulated gene MYADM was positively related to osteocalcin. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that differentially expressed genes were enriched in “systemic lupus erythematosus” and “ECM-receptor interaction”. Gene ontology (GO) enrichment showed that differentially expressed genes may participate in biological processes such as “cell migration” and “cell adhesion”.

Conclusions

In conclusion, this study provides a first insight into transcriptome characteristics of SAPHO syndrome, indicating an over-active neutrophil recruitment in patients and possibly suggesting molecular candidates for further study on diagnosis and pathology of this disease.

Electronic supplementary material

The online version of this article (10.1186/s13023-019-1169-3) contains supplementary material, which is available to authorized users.

The role of Cutibacterium acnes in auto-inflammatory bone disorders

Chronic nonbacterial osteomyelitis (CNO) and SAPHO (synovitis, acne, pustulosis, hyperostosis and osteitis) syndrome are auto-inflammatory disorders manifesting as chronic inflammation of bones and joints, which in SAPHO is often accompanying by skin changes. The aetiology of these diseases is unknown, but includes genetic, infectious and immunological components. It has been proposed that Cutibacterium (formerly Propionibacterium) acnes plays a role in the pathogenesis. In this review, we summarise reported cases of CNO or SAPHO syndrome in which C. acnes has been isolated from bones. To identify cases, a search was done in May 2018 using the MEDLINE Ovid interface (1946 to present). We found 14 publications reporting 98 patients with auto-inflammatory bone disorders, of whom 48 (49%) had positive bone biopsies for C. acnes. This bacterium was more frequently isolated from open biopsies than percutaneous ones (43/69 (62%) vs 1/7 (14%); p = 0.04) and biopsies were more frequently positive in patients who presented with simultaneous skin manifestations (19/36 (53%) vs 4/12 (33%); p = 0.03).Conclusion: In patients with CNO or SAPHO, C. acnes can be isolated from open biopsies suggesting that in these patients, C. acnes might be a pathogen rather than a contaminant. The fact that biopsies are more frequently positive in patients who present with simultaneous skin manifestations suggests that these individuals might have a genetic predisposition for impaired clearance of C. acnes. What is known • Chronic nonbacterial osteomyelitis (CNO) and SAPHO (synovitis, acne, pustulosis, hyperostosis and osteitis) syndrome are auto-inflammatory disorders manifesting as inflammation of bones. Both diseases are an important differential diagnosis in children who present with symptoms of (multifocal) osteomyelitis. • The pathogenesis of CNO and SAPHO is multifactorial emcompassing genetic, infectious and immunological components, including interleukin (IL)-1 dysregulation. There is a controversy as to whether Cutibacterium (formerly Propionibacterium) acnes plays a role in the aetiology of CNO and SAPHO. It has been postulated that the presence of C. acnes might trigger auto-inflammatory chronic inflammation in genetically predisposed individuals. What is new • In patients with CNO or SAPHO, C. acnes can be isolated more frequently from open biopsies, than from percutaneous ones, suggesting that C. acnes might be a pathogen rather than a contaminant. • Biopsies are more frequently positive in patients who present with simultaneous skin manifestations suggesting that these individuals might have a genetic predisposition for impaired clearance of C. acnes. Impaired C. acnes clearance likely leads to increased IL-1 beta (β) production by skin cells, bone cells and phagocytes, which is one of the main cytokines underlying chronic inflammatory bone disorders.

Swellings of the sternoclavicular joint: review of traumatic and non-traumatic pathologies

The sternoclavicular joint (SCJ) is an integral part of the shoulder girdle that connects the upper limb to the axial skeleton.

Swelling of the SCJ is commonly due to trauma, degeneration, infections and other disease processes that affect synovial joints.

This review also focuses on uncommon conditions that could affect the SCJ, including SAPHO (synovitis, acne, pustulosis, hyperostosis, osteitis) syndrome, Friedrich’s disease and Tietze syndrome.

The scope of this review is limited to the analysis of the current evidence on the various conditions affecting the SCJ and also to provide an algorithm to manage these conditions.

Cite this article: EFORT Open Rev 2018;3:471-484. DOI: 10.1302/2058-5241.3.170078

SAPHO syndrome associated with hidradenitis suppurativa and pyoderma gangrenosum successfully treated with adalimumab and methotrexate: a case report and review of the literature

SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome is a rare inflammatory condition describing the combination of skin, bone, and joint manifestations that has a heterogeneous presentation. We report a case of severe SAPHO syndrome in association with hidradenitis suppurativa and pyoderma gangrenosum in a 27-year-old male. The patient had an initial migratory arthritis affecting the knees, ankles, metacarpophalangeal joints, proximal interphalangeal joints, wrists, shoulder, and lower back, which progressed to a persistent arthritis and swelling at the sternum, shoulders, wrists, hands, feet, and lower back. Radiographic changes were consistent with the diagnosis of SAPHO syndrome. Serum proinflammatory cytokine levels were significantly elevated and improved substantially after 3 months of therapy. Rationale for therapy in this patient was the observation that tumor necrosis alpha antagonists have been successfully used in SAPHO syndrome, and since arthropathy was so prominent in our patient, we elected to use adalimumab combined with methotrexate.

Neutrophilic dermatoses: Kids are not just little people

Neutrophilic dermatoses are a group of inflammatory skin disorders characterized by an overactive innate immune system with dysregulation of neutrophils without underlying infectious etiology. The major representative conditions discussed are Sweet syndrome; pyoderma gangrenosum; neutrophilic eccrine hidradenitis; palmoplantar eccrine hidradenitis; subcorneal pustular dermatoses; bowel-associated dermatosis arthritis syndrome; and synovitis, acne, pustulosis, hyperostosis, and osteitis. We will also discuss other neutrophilic conditions present almost exclusively in the pediatric population, including congenital erosive and vesicular dermatosis with reticulated supple scarring and the recently described group of autoinflammatory diseases. The clinical characteristics, diagnostic approach, and treatment management in the pediatric and adult population are discussed.

Recurrent multifocal osteomyelitis in children: Experience in a tertiary care center

INTRODUCTION

Chronic recurrent multifocal osteomyelitis is a rare aseptic bone inflammation that affects pediatric patients. Its management and treatment have not yet been standardized.

METHODS

Retrospective, descriptive study of patients under 14 years of age diagnosed with chronic nonbacterial osteomyelitis (CNBO) in a tertiary hospital. We included patients diagnosed over the last 6 years (2010-2015) who met the Jansson criteria. The clinical and radiological characteristics of CNBO were analyzed, as was the outcome after different therapeutic options.

RESULTS

We report 12 patients, with a mean age of 11 years (±1.6 standard deviation [SD]) and female predominance (10:2). The mean number of foci was 3.5 (±2.2 SD). The most common locations were ankle (58%), clavicle (50%), sternum (33%) and hip (25%). The mean disease duration was 10.5 months (±10.3 SD), and the median time to diagnosis was 2.38 months (range 0.17-16). Bone scintigraphy detected asymptomatic foci in 33% and we detected lytic lesions in 50% through magnetic resonance imaging. Biopsy was performed in 60%; 2/12 (16%) were associated with inflammatory disease and 1/12 (8.3%) later developed lymphoma. In all, 58% received antibiotic therapy with little response, 100% anti-inflammatory agents, 50% systemic corticosteroids, 41.6% methotrexate/pamidronate and 16% anti-tumor necrosis factor (TNF) α. The mean duration of treatment was 14.8 months (±12.4 SD) and 66% had recurrences. Currently, 83% are in clinical remission without treatment.

CONCLUSIONS

When CNBO is refractory to treatment with anti-inflammatory drugs, intravenous pamidronate can be an alternative. Anti-TNF drugs can be considered in patients who fail with pamidronate, as can agents associated with other autoimmune conditions.

SAPHO, autophagy, IL-1, FoxO1, and Propionibacterium (Cutibacterium) acnes

Overt infection by Propionibacterium acnes is lacking in many SAPHO syndromes, and antibiotics have only a transient and incomplete effect, either in SAPHO syndrome or acne. As several auto-inflammatory bone disorders sharing overproduction of IL-1β can mimic SAPHO, this syndrome could partly depend on genetically encoded overproduction of IL-1β. However, cyclic intracellular infections, mostly by P. acnes, can contribute to the enhanced IL-1β release by some skin cells, and probably by bone cells. P. acnes is indeed a powerful trigger of NLRP3-inflammasome activation and IL-1β, leading to osteitis and enhanced mesenchymal cells differentiation in osteoblasts. Recent advances in the understanding of acne suggest that first steps of this disorder are not driven by P. acnes, but by a relative deficiency of FoxO1 within the nucleus of sebaceous cells. A similar defect of FoXO1 in bone cells should also be sought in SAPHO, since repression of FoxO1 gene is found in lesional psoriasis skin, and is associated with an increased number of osteoblasts and high bone mass in mice. FoxO1 selectively promotes IL-1β production, so that its downregulation could help some P. acnes t escape innate immunity and persist in a latent state in bone cells, including mesenchymal stem cells. However, P. acnes itself possibly contributes to FoxO1 downregulation, like H. pylori infection which induces nuclear inactivation of FoxO1 in human gastric cells to slow down autophagic clearance. As bisphosphonates, which often improve SAPHO syndromes, enhance autophagy, it may be worth testing whether their combination with antibiotics is synergistic in SAPHO syndromes.

Propionibacterium acnes biofilm is present in intervertebral discs of patients undergoing microdiscectomy

Background

In previous studies, Propionibacterium acnes was cultured from intervertebral disc tissue of ~25% of patients undergoing microdiscectomy, suggesting a possible link between chronic bacterial infection and disc degeneration. However, given the prominence of P. acnes as a skin commensal, such analyses often struggled to exclude the alternate possibility that these organisms represent perioperative microbiologic contamination. This investigation seeks to validate P. acnes prevalence in resected disc cultures, while providing microscopic evidence of P. acnes biofilm in the intervertebral discs.

Methods

Specimens from 368 patients undergoing microdiscectomy for disc herniation were divided into several fragments, one being homogenized, subjected to quantitative anaerobic culture, and assessed for bacterial growth, and a second fragment frozen for additional analyses. Colonies were identified by MALDI-TOF mass spectrometry and P. acnes phylotyping was conducted by multiplex PCR. For a sub-set of specimens, bacteria localization within the disc was assessed by microscopy using confocal laser scanning and FISH.

Results

Bacteria were cultured from 162 discs (44%), including 119 cases (32.3%) with P. acnes. In 89 cases, P. acnes was cultured exclusively; in 30 cases, it was isolated in combination with other bacteria (primarily coagulase-negative Staphylococcus spp.) Among positive specimens, the median P. acnes bacterial burden was 350 CFU/g (12 - ~20,000 CFU/g). Thirty-eight P. acnes isolates were subjected to molecular sub-typing, identifying 4 of 6 defined phylogroups: IA₁, IB, IC, and II. Eight culture-positive specimens were evaluated by fluorescence microscopy and revealed P. acnes in situ. Notably, these bacteria demonstrated a biofilm distribution within the disc matrix. P. acnes bacteria were more prevalent in males than females (39% vs. 23%, p = 0.0013).

Conclusions

This study confirms that P. acnes is prevalent in herniated disc tissue. Moreover, it provides the first visual evidence of P. acnes biofilms within such specimens, consistent with infection rather than microbiologic contamination.

The prevalence of sacroiliitis in patients with acne vulgaris using isotretinoin

BACKGROUND/OBJECTIVE

Acne vulgaris is a chronic inflammatory disease affecting the pilosebaceous unit in the skin. Isotretinoin is a synthetic vitamin A derivative regarded as the most effective agent in the treatment of acne. There have recently been increasing reports of adverse effects of isotretinoin on the skeletal system. Our aim in this study was to evaluate the rheumatic side-effects triggered by this drug, and particularly the prevalence of sacroiliitis.

MATERIALS AND METHODS

A total of 73 patients receiving isotretinoin due to moderate or severe acne vulgaris were included. All patients were questioned about inflammatory low back pain and musculoskeletal pains during the treatment process. Inflammatory low back pain was evaluated using Assessment of Spondyloarthritis International Society (ASAS) criteria. Patients meeting ASAS criteria were evaluated with radiography and when necessary with sacroiliac magnetic resonance.

RESULTS

The dose range for isotretinoin was between 0.4 and 0.8 mg/kg/day (mean 0.53 mg/kg/day). Treatment lasted for 6-8 months (mean 6.8 months). Lethargy was determined in 37 (50.7%) patients, myalgia in 31 (42.5%) and low back pain in 36 (49.3%). Mechanical low back pain symptoms were present in 20 of the patients describing low back pain and inflammatory low back pain in 16. Acute sacroiliitis was determined in six patients (8.2%) following a sacroiliac magnetic resonance imaging (MRI). Five (83.3%) of the patients with sacroiliitis were female and one (16.7%) was male. No statistically significant difference was determined between male and female patients in terms of prevalence of sacroiliitis (p = 0.392).

CONCLUSION

The incidence of sacroiliitis in patients using isotretinoin is quite high. Patients using isotretinoin must be questioned about sacroiliitis findings and must be subjected to advanced assessment when necessary. Further studies regarding the development of sacroiliitis under isotretinoin therapy are now needed.