A prospective study of 287 patients with polymyalgia rheumatica and temporal arteritis: clinical and laboratory manifestations at onset of disease and at the time of diagnosis.

A prospective study of 287 patients with giant cell arteritis (GCA), including polymyalgia rheumatica (PMR) and temporal arteritis (TA), was conducted during 1987-1994. All patients were evaluated prior to the start of drug treatment. During the same period, 31 patients with GCA, of whom 12 cases had TA, were admitted to other departments in the hospital. At onset of disease, all patients were > or = 50 yr of age. Peripheral arthritis was found in 24.4% of patients with PMR, while none of the patients with TA exhibited such manifestations. Clinical features at onset of disease differed from those appearing at presentation to the hospital. Thus, the gradual development of a full-blown clinical picture may be responsible for the delay in diagnosis of GCA. The majority of cases (80%) presented with "pure' PMR without clinical signs or symptoms of concomitant TA. In a random sample of 68 patients with "pure' PMR, histological examinations of biopsy specimens of the temporal artery revealed inflammatory changes in three patients only (4.4%). Consequently, arterial biopsy in patients with clinical features of PMR only, appears to be unnecessary. Among patients with TA referred to the department of internal medicine, general malaise, loss of weight and sustained fever were prominent manifestations. Such features may thus necessitate a diagnostic arterial biopsy even in the absence of clinical arteritis or myalgia. Both ESR and CRP were within normal levels in 1.2% of the cases. Further clinical and laboratory examinations performed at diagnosis of GCA disclosed only one case of malignancy. Routine chest X-rays did not reveal unexpected pathological findings. Permanent and complete blindness due to arteritis was observed in one patient only. No association between GCA and thyroid dysfunction was detected.