musculoskeletal and connective tissue disorders
Giant Cell Arteritis
Diagnosis of Giant Cell Arteritis
Erythrocyte sedimentation rate (ESR), C-reactive protein, and complete blood count (CBC) Biopsy, usually of the temporal artery Sometimes, temporal artery ultrasound Giant cell arteritis is suspected in patients>55 if any of the following develops, especially if they also have symptoms and laboratory evidence of systemic inflammation: A new type of headache Any new symptom or sign compatible with ischemia of an artery above the neck Jaw muscle pain during chewing Temporal artery or scalp tenderness Unexplained subacute fever or anemia The diagnosis of giant cell arteritis is more likely if patients also have Symptoms and Signs . Physical examination may detect swelling and tenderness, with or without nodularity or erythema, over the temporal arteries, sometimes with loss of a palpable pulse. Temporal arteries can become prominent. A temporal artery that rolls under the examiner’s fingers, rather than collapses, is abnormal. The large arteries of the neck and branches of the aorta should be evaluated for bruits. If the diagnosis is suspected, ESR, C-reactive protein, and CBC are determined. In most patients, ESR and C-reactive protein are elevated; anemia of chronic disease is common. Occasionally, platelets are elevated, and serumalbuminand total protein, if measured, are low. Mild leukocytosis is commonly detected but is nonspecific. If the diagnosis of giant cell arteritis is suspected, biopsy of an artery is recommended. Because inflamed segments often alternate with normal segments, a segment that appears abnormal should be sampled if possible. Usually, the temporal artery is biopsied from the side that is symptomatic, but the occipital artery can also be biopsied if it appears abnormal. The optimal length of temporal artery to remove is unclear, but longer samples, up to 5 cm, increase the yield. The added diagnostic value of contralateral biopsy is small. Treatment should not be delayed to do the biopsy. Because inflammation resolves slowly, the temporal artery biopsy can be done up to 2 weeks after corticosteroid treatment is started. Color Doppler ultrasonography of the temporal artery may detect vessel wall edema, seen as a halo, when performed by experts, and may come to substitute for temporal artery biopsy in the diagnosis of giant cell arteritis ( Diagnosis reference ). Ultrasound of the temporal artery should be done before treatment is started or within 5 days, because corticosteroids decrease the test sensitivity. Among many advantages, the test is noninvasive, involves no exposure to radiation, and can image other cranial vessels. However, the diagnostic usefulness of temporal artery ultrasound is heavily dependent on the ultrasound operator skills and equipment. Imaging of the aorta and its branches should be done at the time of diagnosis and then periodically after, even in the absence of suggestive symptoms or signs (see table). 1.Chrysidis S, Døhn UM, Terslev L, et al: Diagnostic accuracy of vascular ultrasound in patients with suspected giant cell arteritis (EUREKA): a prospective, multicentre, non-interventional, cohort study. The Lancet Rheumatology 3 (12) e865-e873, 2021. doi.org/10.1016/S2665-9913(21)00246-0 