Atypical Signs and Symptoms of Giant Cell Arteritis: A Systematic Review

Background Giant cell arteritis can present with atypical manifestations that delay treatment and risk severe complications. Objectives To comprehensively describe all atypical signs/symptoms of giant cell arteritis. Design In this systematic review, we searched MEDLINE, Embase, and Cochrane Central Register of Controlled Trials from inception to October 2022. Primary research articles that included at least one participant with an atypical sign/symptom of biopsy-proven giant cell arteritis were included. Study screening and data extraction were performed in duplicate. The primary outcome was the proportion of participants with atypical giant cell arteritis features. Time to treatment was compared between participants with atypical giant features only and participants with both typical and atypical features. Results Of 21,828 screened records, 429 studies corresponding to 746 individuals (median [IQR] age 72 [IQR, 66-78] years, 63% female) with at least one atypical feature of GCA were included. Eighty-two percent had both atypical and at least one concurrent typical giant cell arteritis feature, whereas 18% of patients with atypical signs and symptoms only presented with atypical features. Patients with atypical symptoms presented to clinicians earlier than patients with typical features (p < 0.001). There was no difference between groups in proportion to elevated ESR and CRP (82.3% vs. 83.35%, p = 0.91) or mortality rate (8.2% vs. 10.8%, p = 0.42). Patients with atypical features only experienced greater delay in treatment initiation (p < 0.001). The most commonly reported atypical signs/symptoms were vertigo (11.9%), scalp necrosis/ulceration (7.9%), and dry cough (5.8%). Conclusions Eighteen percent of biopsy-proven giant cell arteritis cases with at least one atypical feature have only atypical features and are more likely to experience delays in treatment. Clinicians should be aware of atypical signs/symptoms of giant cell arteritis and order inflammatory markers early to prevent giant cell arteritis-associated morbidity.