Unilateral weak radial pulse in a patient with systemic sclerosis: Takayasu’s arteritis or thoracic outlet syndrome?

Abstract

Dear sir, Takayasu’s arteritis (TA) a chronic large vessel vasculitis that predominantly aVects elastic arteries such as the aorta, its major division branches, and the pulmonary arteries [1]. TA is occasionally called “pulseless disease” because there is diYculty in detecting peripheral pulses that sometime occurs as a result of vascular narrowing. TA is a rare disorder, occurring most frequently in the Far East and aVecting young females more frequently than males. As far as we know, TA has been found in association with several conditions, but there have been only three reports in the literature on concurrent systemic sclerosis (SSc) and TA [2–4]. We report the case of a 37-year-old female who was diagnosed with SSc because of Raynaud’s phenomenon, puVy hands, positive anti-topoisomerase I antibody (Ab) and interstitial lung disease conWrmed by lung biopsy in October 2002 at another university hospital. She had been treated with oral prednisone and cyclophosphamide. The patient was referred to our outpatient clinic for treatment due to continuing complaint of Raynaud’s phenomenon in 2003. On physical examination, Raynaud’s phenomenon and a pitting scar on her right hand were observed. However, the modiWed Rodnan Skin Score (mRSS) was almost zero. We modulated steroid dose and added Ca-channel blocker for peripheral vasodilation. In April 2006, on physical examination we discovered that her left radial pulse was weak. There were no abnormal neurologic Wndings, but her blood pressure was asymmetric, being recorded as 160/90 on the right and 145/75 on the left. There was no bruit audible on auscultation over neck and abdomen. The laboratory results were as follows: leukocyte 8,900/mm3, hemoglobin 12.9 g/dl, platelet 292,000/mm3, erythrocyte sedimentation rate 40 mm/ h; Serum biochemical examination showed normal range of cholesterol and glucose level. Her thyroidal hormone proWle was normal. Serologic investigation revealed that she had positive nucleolar type antinuclear Ab (1:2,560) and positive anti-topoisomerase I Ab. But anti ds-DNA Ab, anti-Ro Ab, anti-La Ab, anti-Sm Ab, c-ANCA, p-ANCA and rheumatoid factor were negative. Based on the detection of the weak left radial pulse and asymmetric blood pressure, we thought that the presence of left vascular lesion was obvious. In the CT angiography, there was stenosis of right common carotid artery, right external carotid artery, thoracic and abdominal aorta (Fig. 1a). The Wndings were compatible with TA [5]. However, there was only slight wall thickening of left subclavian artery. These Wndings could not explain the weak left radial pulse. In other sections of angiography, we found that the left anterior and medial scalenus muscles hemodynamically squeeze the left subclavian artery as the left arm is fully abducted (Fig. 1b). Finally, we discovered that the cause of weak left radial pulse was thoracic outlet syndrome (TOS). We were very fortunate to Wnd TA, because all provocation T.-J. Kim · W.-S. Uhm · J.-B. Jun (&) Department of Rheumatology, The Hospital for Rheumatic Diseases, Hanyang University College of Medicine, Seoul, South Korea e-mail: junjb@hanyang.ac.kr