Giant cell arteritis (also known as temporal arteritis) is an inflammatory vasculitis that often involves medium and large arteries, commonly in patients over 50 years of age, and can cause neurological, ocular and systemic syndromes, such as stroke or aneurysm. It often involves arteries that supply blood to the retina, optic nerve, and superficial temporal arteries. Inflammation of the superficial temporal arteries can lead to pressure pain in the temporal region. Giant cell arteritis is more difficult to diagnose. If you have any suspicions, you should immediately refer the patient to an ophthalmologist or rheumatologist. Some specialists may perform a temporal artery biopsy. A positive biopsy is sufficient for a diagnosis of giant cell arteritis. Some patients with giant cell arteritis have a negative biopsy. This is because only part of the artery is involved and the rest of the artery is not involved. This symptom is known as a jumping lesion. As many as 28% of patients exhibit jumping lesions. In these patients, the ophthalmologist will consider whether the patient’s signs and symptoms are appropriate for steroid hormone therapy. Some patients with giant cell arteritis exhibit pupil dilation due to acute obstruction of the optic nerve blood supply. You can use the 1990 edition of the American College of Rheumatology’s classification criteria for giant cell arteritis for your diagnosis. Three or more positive indicators have a sensitivity of 94% and specificity of 91% for diagnosing this disease. The five criteria include: Erythrocyte sedimentation rate ≥ 50 mm within the first hour in patients over 50 years of age with a new episode of localized headache Abnormalities are present on palpation of the temporal artery when the patient feels tenderness on temporal artery biopsy. A positive biopsy is sufficient for the diagnosis of giant cell arteritis. Indications for a positive biopsy include granulomatous infiltration of the internal elastic membrane rupture of the intimal lumen obstruction. Ultrasonography of the temporal arteries is a new method of screening for giant cell arteritis. It is a noninvasive test, but the accuracy of this method and temporal artery biopsy has not been compared.