Tijdschrift voor geneeskunde vol:64 issue:21 pages:1094-1100
Diagnosis of vasculitis: value of criteria and tests
As vasculitis may affect any blood vessel, irrespective of type, location, and size, manifestations are heterogeneous. At the same time, the presenting features of the individual types of vasculitis may overlap. Still, different vasculitides with indistinguishable clinical presentations may have very different prognoses and treatments. Thus, recognizing vasculitis and determining the distinctive type are important.
Which criteria guide the clinician in differentiating the vasculitides? At present, etiopathogenic mechanisms are incompletely understood and cannot serve as a classification basis. This article discusses the American College of Rheumatology 1990 criteria for the classification of vasculitis and the nomenclature of systemic vasculitides proposed at the Chapel Hill Consensus Conference (1994). Classification criteria provide a standard way to evaluate and report groups of patients in studies, but remain inappropriate to apply in the diagnosis of an individual patient. Up to now, robust and generally accepted diagnostic criteria for the various forms of vasculitis syndromes are lacking.
How then does the clinician reach a diagnosis? The diagnostic approach when confronted with suspected vasculitis and the value of tests are briefly discussed. A low index of suspicion in the proper clinical setting and a knowledge of the individual vasculitis syndromes are keys to the diagnosis. The description of antineutrophil cytoplasmic antibodies (ANCA) has represented a major breakthrough in the approach to small-vessel vasculitis. A definite diagnosis of vasculitis usually requires biopsy of affected tissue or angiography. Tissue data and angiographic findings should be integrated with the clinical and laboratory findings. Accurate diagnosis of the vasculitis type and of the extent of organ involvement sets the stage for prognostication and therapy.