Abstract
Giant cell arteritis (GCA), also known as temporal arteritis, is a chronic vasculitis affecting large- and medium-sized arteries in patients over 50 years old. Untreated GCA can cause serious morbidity like irreversible vision loss, aneurysms, or stroke. We present a case of a patient who developed an acute headache and trismus within hours of undergoing a root canal treatment. Because GCA typically presents more gradually, the sudden onset of symptoms raised concern for dental-related complications or infection, contributing to a delay in considering GCA. This case highlights the importance of maintaining a broad differential and recognizing atypical presentations to ensure timely diagnosis and treatment, thereby reducing the risk of long-term morbidity.