SAPHO syndrome in a patient with ulcerative colitis

Summary: Introduction: The term SAPHO syndrome, which stands for synovitis, acne, hyperostosis, osteitis (SAPHO) was first described by Chamot et al., includes group of conditions that had sterile, inflammatory osteoarticular disorders associated with skin manifestations. While children and young to middle-aged adults are most commonly affected, it can present at any age with anterior chest wall being the most characteristic joint location. In a few cases, SAPHO can be associated with inflammatory bowel disease (IBD) particularly Crohn’s disease. Here we present a unique case of 60-year-old male with ulcerative colitis (UC) who developed SAPHO syndrome. Case presentation: 60-year-old male patient was referred to our Rheumatology department for evaluation of a possible autoimmune disorder. He presented with progressively worsening pain in the right side of the chest radiating to right arm and upper back over the past 4 months, coinciding with a diagnosis of pulmonary embolism. On examination, tenderness of the medial aspect of clavicle was present. His past medical history included UC since 2016, treated with various biologic agents including Infliximab (stopped because of pustular psoriasis), Vedolizumab and then finally Ustekinumab. His routine blood results showed elevated inflammatory markers with ESR of 92 mm/hr. White cell counts, autoimmune panel, liver function test were within normal limits. Imaging studies including chest x ray (Figure 1) and MRI (Figure 2) showed enlargement of the right first rib at the costochondral junction. Chest CT w/o contrast showed reactive proliferative osseous changes with surrounding soft tissue fullness in anteromedial aspect of the right first rib and adjacent sternum. Bone scintigraphy (Figure 3) showed expansile lesion in the distal right first rib with associated hyperostosis and ankylosis of the costochondral junction. Bone biopsy (Figure 4) of right anterior first rib showed reactive bone and costal cartilage and no findings of infection or malignancy. The patient was started on treatment with sulfasalazine, local steroid injections and Zoledronate which provided adequate relief. Summary: The diagnosis of SAPHO syndrome in IBD patients is rare with some studies reporting less than 1% prevalence. Underdiagnosis may contribute to this rarity, as the clinical features of SAPHO syndrome can resemble those of extra intestinal manifestations of IBD. Treatment typically involves use of non-steroidal anti-inflammatory drugs and corticosteroids as first line agents. Other therapies including use of disease modifying antirheumatic drugs (DMARDs), antitumor necrosis factor agents (Anti-TNF), bisphosphonates and calcitonin have shown promising results. Early recognition of this association is important for optimal management and improved outcomes in affected individuals.