Giant cell arteritis restricted to the limb arteries: An overlooked clinical entity

Objective: Giant cell arteritis (GCA) is a systemic vasculitis typically affecting temporal arteries. In at least 15% of cases, GCA also features inflammation of the aorta and its primary branches. Large-vessel inflammation restricted to proximal limb arteries in the absence of temporal and aortic involvement (Limb Restricted, LR) is rare and not well described in literature. Hence, we aim to characterize this neglected clinical entity. Methods: We describe a series of three cases of LR-GCA. All patients were older than 50 years, had increased erythrocyte sedimentation rate (ESR), normal cholesterol and triglycerides serum levels, negative temporal artery biopsy, suggestive F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) findings, and responded to immunosuppressive therapy. We also reviewed all published cases of LR-GCA (76 cases), for a total of 79 patients. Results: Limb claudication was reported in 87% of the patients, and cranial symptoms and polymyalgia rheumatica in 20%. Constitutional symptoms were never reported. Median ESR levels were 66.5 mm/1 h. Upper and lower limb arteries were involved in 86% and 9% of the patients respectively, and the remaining 5% had simultaneous upper and lower limb vessel involvement. Conventional angiography was performed in 63% of the cases, color-doppler ultrasound in 20%, FDG-PET in 14%, and computed tomography angiography in 3%. Conclusion: If temporal biopsy and aortic imaging are negative for GCA in patients older than 50 years with bilateral limb claudication, elevated ESR, and suggestive vascular radiological findings, LR-GCA should be suspected. Upper limb arteries are more frequently involved. Since constitutional symptoms are typically absent in LR-GCA, differential diagnosis with atherosclerotic plaques may be challenging.