Renatta Varma and Anil Patel remind us of the variability in presentation of giant cell arteritis (GCA).1 Another patient's story presents yet another pitfall in GCA diagnosis.
A 76-year-old woman presented to the emergency department with right temporal “head pain.” Her erythrocyte sedimentation rate was 65 mm/h. The diagnosis was “headache, rule out temporal arteritis.” Prednisone, 40 mg per day, was prescribed, and the patient was referred for follow-up examination. Four days later, the patient's tenderness to percussion over the right temporal area persisted, and I increased the prednisone dosage. A biopsy was performed 2 days later.
The biopsy results, available 1 week later, showed no evidence of GCA, so the ophthalmologic surgeon stopped the patient's prednisone. The patient returned to me 4 days later with increasing “head pain.” We discussed the possibility of false-negative biopsy findings, and I prescribed prednisone again (and osteoporosis prophylaxis). A consultation was arranged with a rheumatologist who concurred with the diagnosis of biopsy-negative CGA and continued to treat the patient accordingly.
Although the only confirmatory test for GCA is a positive biopsy, nondiagnostic biopsy specimens do not exclude the diagnosis. It is commonly accepted that, because of the patchy involvement of the arteries, biopsies may be nondiagnostic in many patients. Thus, because biopsies are invasive, some authors even suggest that biopsy may not be necessary.2,3
Furthermore, corticosteroid therapy, which should be started without delay, rapidly reduces the chance of a positive biopsy result.2 One week of corticosteroid treatment may reduce the chance of obtaining a positive biopsy to 10%.4 Therefore, biopsy should be performed within the first few days of therapy.4
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Competing interests: None declared.