A high erythrocyte sedimentation rate (ESR) is considered to be a hallmark
of giant cell arteritis (GCA) and one of the 1990 American College of Rheum
atology classification criteria. We studied 248 patients with GCA to assess
the frequency and clinical features of patients with GCA and an ESR <50 mm
/h. Ten patients had a low ESR(43.1 +/- 4.9 mm/h) and in the remaining 238,
the ESR was greater than or equal to 50 mm/h (96.4 +/- 23.6). None of the
patients with an ESR less than 50 had a completely normal ESR. The spectrum
of the disease in both groups was very similar. Both groups required simil
ar corticosteroid therapy and had a similar outcome. The ESR, analysed as a
continuous variable, showed a significant positive correlation with other
parameters reflecting the acute-phase response such as presence of anaemia,
weight loss and fever. We suggest that in patients with a clinical picture
compatible with GCA, the use of an ESR greater than or equal to 30 mm/h as
the main laboratory parameter to consider the possibility of GCA would be
enough to arise the suspicion and prevent cases of GCA being missed.