Editing Giant cell arteritis (section)

===Associated conditions===
The [[varicella-zoster virus]] (VZV) [[antigen]] was found in 74% of temporal artery biopsies that were GCA-positive, suggesting that the VZV infection may trigger the inflammatory cascade.<ref>{{cite journal | vauthors = Gilden D, White T, Khmeleva N, Heintzman A, Choe A, Boyer PJ, Grose C, Carpenter JE, Rempel A, Bos N, Kandasamy B, Lear-Kaul K, Holmes DB, Bennett JL, Cohrs RJ, Mahalingam R, Mandava N, Eberhart CG, Bockelman B, Poppiti RJ, Tamhankar MA, Fogt F, Amato M, Wood E, Durairaj V, Rasmussen S, Petursdottir V, Pollak L, Mendlovic S, Chatelain D, Keyvani K, Brueck W, Nagel MA | title = Prevalence and distribution of VZV in temporal arteries of patients with giant cell arteritis | journal = Neurology | volume = 84 | issue = 19 | pages = 1948–1955 | date = May 2015 | pmid = 25695965 | pmc = 4433460 | doi = 10.1212/WNL.0000000000001409 }}</ref>

The disorder may co-exist (in about half of cases) with [[polymyalgia rheumatica]] (PMR),<ref name="half" /> which is characterized by sudden onset of pain and stiffness in muscles ([[pelvis]], [[shoulder]]) of the body and is seen in the elderly. GCA and PMR are so closely linked that they are often considered to be different manifestations of the same disease process. PMR usually lacks the [[Skull|cranial]] symptoms, including headache, pain in the jaw while chewing, and vision symptoms, that are present in GCA.<ref>{{Cite web|url=https://bestpractice.bmj.com/topics/en-gb/177/differentials|title=Giant cell arteritis|website=BMJ Best Practice|access-date=2019-11-25}}</ref>

Giant cell arteritis can affect the aorta and lead to [[aortic aneurysm]] and [[aortic dissection]].<ref name=":0" /> Up to 67% of people with GCA having evidence of an inflamed aorta, which can increase the risk of aortic aneurysm and dissection.<ref name=":0">{{cite journal | vauthors = Chen JJ, Warrington KJ, Garrity JA, Prasad S | title = Is Routine Imaging of the Aorta Warranted in Patients With Giant Cell Arteritis? | journal = Journal of Neuro-Ophthalmology | volume = 37 | issue = 3 | pages = 314–319 | date = September 2017 | pmid = 28614098 | doi = 10.1097/WNO.0000000000000538 | s2cid = 3747982 }}</ref> There are arguments for the routine screening of each person with GCA for this possible life-threatening complication by imaging the aorta. Screening should be done on a case-by-case basis based on the signs and symptoms of people with GCA.<ref name=":0" />