PAN's labyrinth: a multidisciplinary delayed diagnosis and patient's perspective.

Polyarteritis nodosa (PAN) is a rare, severe form of vasculitis affecting medium-sized vessels. It manifests as a multisystem syndrome, and may be associated with hepatitis B virus-associated PAN (HBV-PAN) although the incidence of this is declining with better vaccination strategies and awareness of bloodborne virus screening. We report a case in which a patient displayed many classical features of the disease, occurring separately over a period of months and leading to contact with various medical specialties. Managing each symptom in isolation led to a number of misdiagnoses (including testicular cancer) and the patient experienced considerable psychological stress and morbidity as a result. The case was complicated by acute pancreatitis developing after an initial treatment response. This may have been iatrogenic (as a consequence of either entecavir or steroids) or secondary to PAN. For our patient, this led to a protracted clinical course but eventual complete resolution of both pathologies. 2016 BMJ Publishing Group Ltd.