A 36-year-old man who presented with a 9-year history of recurrent bilateral pain in the gluteal region accompanied by pain in the lumbosacral area was admitted to our hospital in July 2014. His medical history revealed that he was diagnosed with AS through a comprehensive clinical assessment in 2012. Celecoxib capsules (0.2 g po bi-diurnally) were taken for 2 years to control his symptoms. During the last 2 months of the 2-year treatment period, owing to irregular use, the condition worsened. Laboratory test results were as follows: human leukocyte antigen B27 (HLA-B27), positive; C-reactive protein (CRP), 23.7 mg/L; and erythrocyte sedimentation rate (ESR), 48 mm/h. Radiography showed grade 2 to 3 bilateral sacroiliitis and MRI of the spine showed inflammation at the attachment point ( Figure S1 ). Based on the above results, ankylosing spondylitis diagnosis was established, and the presentation met the modified New York criteria.
During hospitalization, recombinant human tumor necrosis factor-alpha receptor II (IgG Fc fusion protein injection [YISAIPU , 25 mg ih biweekly]) was administered to the patient. The patient's pain gradually resolved, and the drug was discontinued after 1 year. In 2017, the patient suffered from recurrent pain in both hips and was treated again with recombinant human tumor necrosis factor-alpha receptor II (IgG Fc fusion protein for injection [YISAIPU, 25 mg ih biweekly) to control the condition, and the symptoms resolved. In 2019, the patient discontinued YISAIPU, and subsequently developed neck stiffness and pain, significantly limited mobility, and a scaling rash on the scalp, left calf, and feet, which did not improve after YISAIPU was re-administered. Therefore, adalimumab injection (40 mg ih once every 2 weeks) was administered. The patient's neck pain and rash gradually subsided.
In January 2022, the patient was re-admitted to our hospital for chest and back pain and difficulty in turning over. However, adalimumab did not relieve his symptoms. In addition, the patient developed a pustular rash on the scalp, left calf, and both feet, which was itchy and gradually increased in size. Other symptoms included obvious abdominal pain after eating and diarrhea. Laboratory test results were as follows: CRP, 66.2 mg/L and ESR, m/h. Electronic colonoscopy revealed ulcers in the terminal ileum and multiple ulcers in the colon and rectum. Free inflammatory exudates were also observed ( Figure S2 ). The skin disease was diagnosed as palmoplantar pustulosis (PPP) and hidradenitis suppurativa through consultation with dermatologists. On imaging, CT showed inflammatory changes of the breastbone. Notably, the characteristic "bull's head sign," indicated by significant tracer enrichment in the front wall of the chest, was observed on bony scintigraphy. Through comprehensive clinical assessment, a diagnosis of SAPHO syndrome was established ( Figures 1A-C ).
The patient was treated as follows: methotrexate tablets (12.5 mg po once a week) and mesalazine enteric-coated tablets (0.80 g po bi-diurnally) for 3 months, adalimumab injections (80 mg ih, once every 2 weeks) for 1 month, and adalimumab injection (40 mg ih, once every 2 weeks) for 3 months. The above treatment effectively relieved the patient's chest and lower back pain, and diarrhea, but did not have any effect on the rash. After discussion with physicians, adalimumab (40 mg ih, once every 2 weeks) was discontinued and switched to tofacitinib (5 mg po bi-diurnally). The patient's rash subsided significantly after 1 month ( Figures 1D, E ), and the chest and back pain was further relieved ( Figure 2 ). The CRP level was 2.0 mg/L and ESR was 10 mm/h.