particularly raised ALP- alkaline phosphatase Platelets may also be elevated. Biopsy The gold standard for diagnosing temporal arteritis is biopsy, which involves removing a small part of the vessel under local anesthesia and examining it microscopically for giant cells infiltrating the tissue. However, a negative result does not definitively rule out the diagnosis; since the blood vessels are involved in a patchy pattern, there may be unaffected areas on the vessel and the biopsy might have been taken from these parts. Unilateral biopsy of a 1.5–3 cm length is 85-90% sensitive (1 cm is the minimum). Characterised as intimal hyperplasia and medial granulomatous inflammation with elastic lamina fragmentation with a CD 4+ predominant T cell infiltrate, currently biopsy is only considered confirmatory for the clinical diagnosis, or one of the diagnostic criteria. Medical imaging Radiological examination of the temporal artery with ultrasound yields a halo sign. Contrast-enhanced brain MRI and CT are generally negative in this disorder. Recent studies have shown that 3T MRI using super high resolution imaging and contrast injection can non-invasively diagnose this disorder with high specificity and sensitivity. Treatment GCA is considered a medical emergency due to the potential of irreversible vision loss. Corticosteroids, typically high-dose prednisone (1 mg/kg/day), should be started as soon as the diagnosis is suspected (even before the diagnosis is confirmed by biopsy) to prevent irreversible blindness secondary to ophthalmic artery occlusion. Steroids do not prevent the diagnosis from later being confirmed by biopsy, although certain changes in the histology may be observed towards the end of the first week of treatment and are more difficult to identify after a couple of months. The dose of corticosteroids is generally slowly tapered over 12–18 months. Oral steroids are at least as effective as intravenous steroids, except in the treatment of acute visual loss where intravenous steroids appear to offer significant benefit over oral steroids. Short-term side effects of prednisone are uncommon but can include mood changes, avascular necrosis, and an increased risk of infection. Some of the side effects associated with long-term use include weight gain, diabetes mellitus, osteoporosis, avascular necrosis, glaucoma, cataracts, cardiovascular disease, and an increased risk of infection. It is unclear whether adding a small amount of aspirin is beneficial or not as it has not been studied. Injections of tocilizumab may also be used. Tocilizumab is a humanized antibody that targets the interleukin-6 receptor, which is a key cytokine