Polyarticular arthritis as presenting feature of farber disease: a lysosomal storage disease involving inflammation

Introduction Farber lipogranulomatosis (Farber Disease; FD) is an ultra-rare lysosomal storage disorder resulting from the inherited deficiency of the enzyme acid ceramidase, and the accumulation of the lipid substrate, ceramide. Ceramide is a pro-inflammatory and pro-apoptotic lipid that has been implicated in the pathogenesis of cartilage disorders. Farber Disease has a heterogeneous presentation ranging from a severe phenotype with respiratory and CNS involvement with an average life expectancy of 1.3 years, to a moderate phenotype, which generally includes joint swelling, contractures and pain. The clinical similarity between the moderate Farber phenotype and the more severe forms of Juvenile Idiopathic Arthritis (JIA) suggests that moderate Farber Disease cases may be diagnosed as JIA in some cases.