Takayasu’s arteritis (TA) is a granulomatous vasculitis of the large arteries. It typically produces segmental arterial narrowing and occlusion, but aneurysm formation is uncommon.1 Subclavian artery aneurysm presenting with Horner’s syndrome is very rare.2 We report on a patient with Horner’s syndrome caused by subclavian artery aneurysm in TA. A 37 year old Korean man was admitted because of right side ptosis and anhidrosis. He had visited the ophthalmology department three weeks previously. Initially, his margin reflex distance 1 (MRD1) was 1.5 mm (right) and 3.0 mm (left). The neostigmine test was performed, but the MRD1 did not change. After administration of phenylephrine 1 drop, however, MRD1 was improved to 3.0 mm in the right eye. Horner’s syndrome was diagnosed. He had no trauma history. He did not complain of any claudication, pain, or dizziness. His blood pressure was 110/70 mm Hg in both arms and pulse rate 80 beats/min. Complete blood counts, serum protein, and urine analysis were normal. Antinuclear …
