An Atypical Presentation of Giant Cell Arteritis in an Elderly Patient: Diplopia and Fever Masked by Pneumonia.

Giant cell arteritis (GCA) is a chronic vasculitis typically affecting individuals over 50 years of age, often presenting with headache, jaw claudication, scalp tenderness, or visual symptoms. We report an 86-year-old male with psoriasis and hypertension who presented with cough, fever, night sweats, headache, and binocular diplopia, initially managed as pneumonia and possible stroke. Despite antibiotics, his fever and ocular symptoms persisted. Elevated inflammatory markers and temporal artery ultrasound confirmed GCA. Prompt corticosteroid therapy led to clinical improvement. This case highlights an atypical presentation of GCA masked by respiratory infection, emphasizing the importance of early suspicion to prevent irreversible vision loss.