The major aim of descriptive clinical studies should be to define identifiable subgroups and syndromes for their prognostic and therapeutic importance. Prognosis is coming into its own as a discipline1 and remains the hidden question behind the patient's desire to know the diagnosis. Clinicians must incorporate it into their explanation or run the risk of being like the physician in Matthew Arnold's quatrain:
Nor bring to watch me cease to live some doctor, full of phrase and fame to shake his sapient head and give the ill he cannot cure a name.
To deliver a diagnosis without elaborating on what it means for the future is to send the patient to other sources for the information, many of which he cannot use properly. The diagnosis of vasculitis is one such potential trouble spot. A whole spectrum of conditions is included under that simple label, among which can be found