Background The term SAPHO syndrome describes a rare, probably underdiagnosed and heterogeneous disease entity. Characteristic disease features include skin, bone and joint manifestations and a predisposition for involvement of the anterior chest wall. In recent years, diagnostic tools for the detection of the disease have improved as well as treatment options.
Objectives To evaluate the current course of diagnosis, to assess the patients’ disease burden and to describe the disease manifestations currently defining the term “SAPHO syndrome” in a nationwide german cohort.
Methods Patients were recruited from a university rheumatology centre in southern Germany and via a nationwide support group for SAPHO patients. After the patients’ written informed consent was obtained, the patients’ medical records describing the diagnosis of SAPHO were collected. In addition, patients were asked to complete a questionnaire on the course of diagnosis and actual burden of the disease. The plausibility of diagnosis was reviewed by two independent experienced rheumatologists (MW and MG) by means of the attached medical records.
Results Of 120 patients who were contacted by email (n=99) or personally (n=21), 77 agreed to participate in the investigation. Upon review of the medical records, 63 patients with SAPHO diagnosis according to the diagnostic criteria were identified and included in the analysis. 51 (80.9%) patients were female, 12 (19.1%) patients were male. The mean age was 48.1 ± 11.8 years, the time since diagnosis 6.8 ± 4.8 years.
The number of physicians consulted until the final diagnosis was identified, was 5.7 ± 3.4. The specialities of the final diagnosing physicians were rheumatologists in 70%, internists in 10% and others in 30%. On average, the number of imaging procedures performed per patient until diagnosis was as follows: 5.6 x-rays, 3.5 MRIs, 2.2 CT scans and 1.9 bone scintigraphies. The patients´ overall satisfaction with the course of diagnosis was 23.0 ± 28.9 on a visual analogue scale (VAS) from 0 (not content at all) to 100 (very content).
Leading disease manifestations according to the patients and verified in the medical records were arthralgia or arthritis of sternoclavicular joints in 55%, inflammatory back pain in 52%, pustulosis palmoplantaris in 45%, osteitis in 38%, hyperostosis in 35%, recent or current acne in 25%, psoriatic skin lesions in 25% and sacroiliitis in 22%.
The disease burden as stated by the patients was pain with a mean value of 45.7 ± 25.9 on a 100 mm VAS and functional impairment with a mean health assessment questionnaire (HAQ) result of 0.84 ± 0.61. Patients with inflammatory back pain (n=33) had a mean BASDAI of 5.46 ± 1.88 and a mean BASFI of 5.08 ± 2.27.
Conclusions Preliminary data of this large and current SAPHO survey reflects course of diagnosis, disease burden and clinical manifestations in a nationwide cohort. Despite diagnostic improvements in recent years, diagnosing the syndrome still takes years and involves multiple health care specialists as well as imaging modalities. Reasons may include heterogeneity of the disease and low awareness for this rare disease. Our cohort further gives a current overview of the leading disease manifestations of SAPHO patients in Germany and especially shows unsatisfactory results concerning the overall disease burden despite improved treatment options.
Disclosure of Interest None Declared