Giant Cell Arteritis in the Third Decade of Life: A Case for Expanded Clinical Suspicion.

Giant cell arteritis (GCA), also known as temporal arteritis, is the most common idiopathic systemic vasculitis in middle-aged adults, predominantly involving large and medium-sized arteries. We report an unusual case of a 34-year-old woman with a five-year history of migraines who developed symptoms, including headache, transient vision loss, jaw claudication, and a 5 kg weight loss over two months. Physical examination revealed scalp tenderness, with no other notable findings. Laboratory investigations showed an elevated erythrocyte sedimentation rate (ESR) of 85 mm/hr and a C-reactive protein (CRP) level of 50 mg/L. Ultrasound of the temporal artery demonstrated thickening with the characteristic "halo" sign, and a biopsy confirmed inflammatory changes with multinucleated giant cells. Treatment with high-dose prednisolone resulted in remission, and the patient was discharged with a follow-up plan in place. GCA predominantly affects the superficial temporal arteries, with irreversible vision loss being its most serious complication. Prompt diagnosis and treatment are critical. The diagnosis relies on clinical features, elevated inflammatory markers, imaging studies, and histopathological confirmation. According to the European Alliance of Associations for Rheumatology (EULAR) guidelines, temporal artery ultrasound showing a non-compressible "halo" sign is recommended for diagnosis. Further studies are needed to investigate the potential connection between migraines and GCA. This case underscores the rarity of GCA in individuals under 50 and highlights the possibility of GCA developing in younger patients with a longstanding history of migraines.