ABSTRACT

Even though PAN was described many years ago, there has been little progress in understanding its cause or component subgroups, in part, due to its rarity. It has a wide range of disease onset age and clinical symptoms and signs in addition to major differences between subgroups in terms of relapses, survival rates and recommended treatment strategies. Most of PAN subphenotypes demonstrate different clinical courses and therefore may be different diseases rather than a spectrum of the same disease. There is a need to better understand the subphenotypes of PAN in order to research into epidemiologic and aetiologic associations, necessary to develop improved therapies.