**4. Literature review**

The SAPHO syndrome is a rare entity that was first described in the 1980s [3]; since then many cases have been diagnosed in different regions, and it seems to maintain a certain geographic distribution, in which an increase in prevalence in Central European countries [4]. The syndrome can appear at any age, but it usually occurs in childhood and adolescence and usually affects the female gender [5]. Many authors have questioned the SAPHO syndrome as an independent entity since its discovery [6], although nowadays it seems that it is widely accepted, given its clinical and radiological characteristics that differentiate it from other diseases. Its physiopathology remains to be clarified. In the literature there are few cases described which hinder the development of controlled clinical trials to find an adequate treatment. Current treatments and their benefits are based on personal experiences [7]. In most cases NSAIDs manage to control the pain and inflammation of the affected joints, but cases in which this medication is not effective pose a difficulty for medical staff. Intravenous bisphosphonates, such as pamidronate and zoledronate, seem to be the most effective drugs due to the experiences described to date [8]. However, a suitable dosage has not yet been found. It is also being tested with another type of medication such as TNF-α antagonists [9, 10], which may be effective, but more studies and a larger number of patients are needed in order to obtain significant results.
