Large vessel arteritis: a diagnostic challenge in the elderly.

Takayasu arteritis is a rare form of chronic inflammatory arteritis affecting large vessels, predominantly the aorta and its main branches. Those at highest risk are adolescent girls and women in their 2nd and 3rd decade of life, and this disease is most frequently seen in Japan, Southeast Asia, India, and Mexico. An elderly woman with Takayasu arteritis of late onset, an extremely unusual disorder in the Western world, is described. A 67 year old woman presented with a two month history of bilateral forearm pain associated with coldness, numbness, and stiffness. She had claudication symptoms in the upper extremities, asthenia, and loss of 6– 8 kg of body weight. She was hypertense. Physical examination revealed the absence of a bilateral radial pulse and arterial pressure in the upper extremities. Subclavian and axillary artery bruits were audible. Redness of the forearms and hands with trophic changes to the nails were seen. Retinopathy and temporal arterial tenderness or nodularity were not seen. Laboratory data showed an erythrocyte sedimentation rate of 101 mm/ hour, and a C reactive protein of 61.9 mg/litre (normal range, 0–5). Doppler ultrasonography of the renal arteries and an echocardiogram were normal. Magnetic resonance angiography of the aortic arch and its branches (fig 1) showed total proximal stenosis of both the subclavian arteries and a significant filiform stenosis of the right vertebral artery, which had an inverted flow. Bilateral temporal artery biopsy results were negative. Treatment with 0.5 mg/kg/day of prednisone was started, and significant clinical and laboratory improvement was seen. The corticosteroid dose was progressively reduced, and the patient was well one year later. The differential diagnosis of Takayasu arteritis includes other causes of aortitis and large vessels arteritis but, because of the age of our patient, giant cell arteritis is the most likely. These disorders are not mutually exclusive, but are overlapping, because they are histologically similar and share the same pathogenicity. In addition, giant cell arteritis involves the aorta and its large branches in up to 15% of cases, and approximately 50% of these have a negative temporal artery biopsy result. Normally both diseases can be differentiated on clinical grounds. The most discriminatory factors that led to the correct diagnosis in 95% of patients are age of 40 years at disease onset, ethnic background, clinical signs of upper limb vascular insufficiency, shoulder stiffness, and scalp tenderness. The diagnosis is made by vascular imaging findings (proximal stenotic lesions predominate and tend to be bilateral) and American College of Rheumatology criteria (table 1). This patient fulfilled five of the six American College of Rheumatology specific diagnostic criteria. Vascular imaging is crucial in making the correct diagnosis in patients with large vessel giant cell arteritis. Aortitis does not lead to arterial obstruction, but leads to arterial dilatation and aneurysm formation, and most often affects the distal subclavian artery. A real diagnostic dilemma appears when, as in this patient, the clinical presentation is similar (aortic arch syndrome without cranial symptoms), laboratory findings are non-specific, temporal biopsy results are negative, and age is a confusing feature. In such cases, giant cell arteritis with large artery involvement and Takayasu arteritis of late onset have to be considered. This case suggests that Takayasu arteritis may be underdiagnosed in the elderly in the Western world.