Adolescent-Onset Takayasu Arteritis with Vertebral Steal Syndrome and Non-bifurcating Carotid Arteries: A Rare Case from Pakistan.

Background: Takayasu arteritis (TA) is a rare chronic vasculitis primarily affecting the aorta and its major branches, often presenting diagnostic challenges due to nonspecific symptoms, particularly in adolescents. This case highlights a rare adolescent-onset TA with unique vascular findings in Pakistan. Case presentation: A 17-year-old female presented with a 1-year history of fever, 40 kg weight loss, and vague abdominal discomfort. Physical examination revealed absent left arm pulses, vascular bruits, and asymmetric blood pressure. Laboratory tests showed anemia, elevated inflammatory markers (ESR 62 mm/h, CRP 66 mg/L), and hyperferritinemia. CT angiography confirmed thoracic aortic mural thickening, left subclavian artery occlusion, vertebral steal syndrome, and nonbifurcating carotid arteries. The diagnosis of TA was established using modified Ishikawa and 1990 ACR criteria. Management and outcomes: The patient received pulse methylprednisolone, monthly cyclophosphamide, and antihypertensives. Symptoms resolved within 3 months, with normalized inflammatory markers and stable vascular status at 1-year follow-up. Conclusion: This case underscores the importance of considering TA in adolescents with constitutional symptoms and pulse deficits. Early imaging and immunosuppressive therapy led to favorable outcomes. Vertebral steal syndrome and nonbifurcating carotid arteries add educational value, emphasizing clinical vigilance in resource-limited settings.