A patient with familial Takayasu's arteritis presenting with fever of unknown origin.

Takayasu's arteritis rarely presents with fever of unknown origin. We describe a 14-year-old girl who was admitted with a 2-month history of fever of unknown origin associated with vague pain in her left upper arm. The constitutional symptoms responded to a trial of steroid therapy for suspected collagen-vascular disease, but flared up when the dose was tapered. An asymmetric radial pulse was recognized incidentally during follow-up examination; diagnosis of Takayasu's arteritis was confirmed by Duplex ultrasonography and angiography. Takayasu's arteritis must be considered when evaluating children with fever of unknown origin, especially those with a positive family history. Careful assessment of the peripheral vascular system with better interpretation of limb symptoms should allow early, appropriate treatment to prevent irreversible vascular damage.