Sternocostoclavicular hyperostosis and the impact of diagnostic delay: Comment on the article by van der Kloot et al

We read with great interest the article by van der Klootet al, recently published in Arthritis Care & Research,regarding the diagnostic delay in sternocostoclavicular hyperostosis(SCCH) (1). We fully agree with van der Kloot etal, both on the detrimental consequences of a delayeddiagnosis of SCCH on various aspects of the quality of life,and on the need for greater awareness of the anterior chestwall (ACW) pain syndromes by the general practitioners.In 1987, Kahn suggested the acronym SAPHO (whichstands for synovitis, acne, pustulosis, hyperostosis, andosteitis syndrome) in order to unify various conditionscharacterized mainly by osteitis/hyperostotic lesions ofthe ACW (2). Therefore, SAPHO syndrome can be considereda “useful concept” that unifies several disorders sharingsome clinical, radiologic, and pathologic characteristics,especially osteitis/hyperostotic lesions of the ACW.This means that the understanding of SAPHO syndrome isalso very important in musculoskeletal radiology, sincesuch awareness could facilitate the differentiation fromother entities that produce similar radiographic findingsbut have different prognoses and treatments, such as osteomyelitis,Ewing’s sarcoma, metastasis, and Paget’s diseaseof bone (3).Our work, previously published in Arthritis Care & Research,indicated that SCCH represents the first osteoarticularsymptom in 70% of patients with SAPHO syndromefollowed in our tertiary referral rheumatology unit(4). In our experience, the diagnostic delay led to theexecution of inappropriate investigations and the prescriptionof inadequate treatment. In addition, we reported that19 patients had a history of several admissions to theemergency room for a suspected acute cardiac event. Themedian ages, both at the time of the first osteoarticularsymptom of the disease and at the time of the diagnosis,are shown in Table 1. It is also worth recalling that skinlesions may not be accounted for when they are eitherepisodic or appear after bone lesions.We would like to point out that SCCH is the typicaltarget of SAPHO syndrome, representing the mainstay ofthe diagnosis, but it is not pathognomonic of the disease. Asimilar involvement may also be seen in spondylarthropathies,especially in psoriatic arthritis (PsA). In PsA, however,SCCH is more frequently a late complication of thedisease and does not usually involve the medial end of theclaviculae. We think osteitis/hyperostosis of this difficultanatomic site should be regarded as a distinguishing featureof SAPHO syndrome.In conclusion, we agree that diagnostic delays are relevant,but they could be due to the fact that the first referralof these patients is usually not to a rheumatologist. Thereforewe firmly hope, as already suggested (4), that otherspecialists such as dermatologists, emergency room doctors,and general practitioners have greater confidence inrecognizing this condition