Giant cell arteritis (GCA) is a common form of granulomatous inflammation of large blood vessels. It can cause irreversible blindness in nearly 20% of untreated cases. It has an incidence of 15-30 per 100,000 persons aged 50 years and over in North American and European countries. GCA is a medical emergency and requires early confirmation of diagnosis and initiation of treatment. Recent development in non-invasive imaging modalities, with higher sensitivities and specificities than temporal artery biopsy (TAB), improved the standard for GCA diagnosis. The recent updates on British Society for Rheumatology guidelines elaborated on the role of ultrasound (US) in the diagnosis of GCA and use of the guidelines provides a new approach for GCA confirmatory diagnosis. A search was conducted using EMBASE and Medline databases to identify recent published research on the diagnosis of GCA. Only human studies published in English between 2010 to 2020 were considered in this systematic narrative review. This review also summarises the evidence available for non-invasive imaging and recommends an approach combining the recently published algorithm for diagnosis decision making of cranial GCA using scoring system. This review proposes a combined approach to use a clinical diagnostic decision making in suspected cranial GCA and use the scoring system based on the clinical history, examination findings, laboratory results and the imaging results combined to give a score to diagnose GCA from other vasculitides. The approach to investigate a case of GCA needs to be modified and should include newer imaging techniques available and new diagnostic criteria should be used in combination with the rapid access pathways for clinical decision.
View Full Article