What signs, symptoms, or laboratory values are diagnostic for giant cell (temporal) arteritis?
No single laboratory test or physical finding by itself is useful to identify patients with giant cell arteritis (GCA); even the classic hallmarks of GCA were not very predictive. This study was unable to determine whether several findings taken together increase the odds. Even an erythrocyte sedimentation rate (ESR) greater than 100 mm/h only increases the odds of a positive temporal artery biopsy 3-fold, which is in the low range. However, an ESR less than 40 mm/h moderately predicts a negative biopsy. If you suspect GCA, start treatment while awaiting test results.
