An evaluation of criteria for polymyalgia rheumatica.
There has been little basis on which to standardise a diagnosis of polymyalgia rheumatica (PMR), and so 11 rheumatology units in the south and west of Great Britain have collaborated in a study to evaluate possible criteria. Symptoms and laboratory findings claimed to be of diagnostic value in PMR were included in an analysis of the features of 236 patients considered to have unequivocal PMR and 70 patients thought to have possible PMR. The results were compared with similar information from 253 patients with conditions that mimic PMR and from 201 consecutive new presentations to outpatients. The 7 most valuable criteria for differentiation were bilateral shoulder pain or stiffness, onset of illness of less than 2 weeks' duration, initial ESR greater than 40 mm/h, duration of morning stiffness exceeding 1 hour, age 65 years or more, depression and/or weight loss, and bilateral tenderness in the upper arms. We suggest that a patient might be regarded as having probable PMR if any 3 or more of these criteria are fulfilled, or if at least 1 criterion coexists with a clinical or pathological abnormality of the temporal artery. A standardised therapeutic test with prednisolone has value in making the diagnosis of PMR more certain.