Investigations

The required investigations in temporal arteritis show:

• raised ESR*:
  • generally above 70 mm/hr
  • often more than 100 mm/hour
• elevated CRP in active disease
• normochromic, normocytic anaemia and elevated platelet count may be seen
• 1/3 of the patients have mildly abnormal liver function tests, particularly alkaline phosphatase (1)
• tenderness and lack of pulsation of one or both temporal arteries
• temporal artery biopsy diagnostic but may miss focal lesions and necessitate repeat biopsy

N.B. temporal artery biopsy remains positive for up to 40 hours after the initiation of steroid therapy.

Other advanced investigations include (1):

• duplex ultrasound
• computer tomography (CT)
• magnetic resonance imaging (MRI)
• 18F-FDG-PET

* prevalence of temporal arteritis with a normal erythrocyte sedimentation rate is unknown but estimated to be 2 to 8.7 percent of all cases of temporal arteritis (2).

Reference:

• (1) Warrington KJ, Matteson EL. Management guidelines and outcome measures in giant cell arteritis (GCA). Clin Exp Rheumatol 2007;25(Suppl.47): s137-s141.
• (2) Wong RL. Korn JH. Temporal arteritis without an elevated erythrocyte sedimentation rate : Case report and review of the literature.The American Journal of Medicine 1986;80(5): 959-964.