title: The diagnosis of vasculitis.
abstract: Early diagnosis of primary systemic vasculitis is important to allow the early commencement of therapy in order to avoid damage and poor outcomes. The heterogeneous nature of vasculitis presents a diagnostic challenge which may hinder early diagnosis. Anti-neutrophilic cytoplasmic antibody testing has been of particular benefit in defining a subgroup of small-vessel vasculitides and facilitating their earlier diagnosis. Suspicion of vasculitis is an important first step to begin a process of investigation to make or refute the diagnosis. No useful diagnostic criteria exist, but classification criteria have been developed to permit a vasculitis patient to be placed in a diagnostic subgroup. The exclusion of vasculitis 'mimics' and secondary causes of vasculitis are components of diagnosis, which otherwise relies on the recognition of a compatible clinical presentation supported by specific laboratory or imaging tests and confirmatory histology. When the diagnosis remains uncertain, observation over time, repeat investigation and a therapeutic trial may improve the probability of the diagnosis or identify an alternative disease.
authors.affiliation: Addenbrooke's Hospital, Renal Unit, Cambridge, UK. dj106@cam.ac.uk
authors.forename: David
authors.initials: D
authors.lastname: Jayne
mesh_terms: D019268:Antibodies, Antineutrophil Cytoplasmic / Q000032:analysis; D042241:Early Diagnosis; D005500:Follow-Up Studies; D014890:Granulomatosis with Polyangiitis / Q000175:diagnosis / Q000276:immunology; D006801:Humans; D055806:Microvessels / Q000473:pathology; D014657:Vasculitis / Q000145:classification / Q000175:diagnosis* / Q000276:immunology
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic