The key difference between Takayasu arteritis (TAK) and giant cell arteritis (GCA) is the age of the patients affected by the disorders. Takayasu arteritis affects younger patients, generally less than 40 years of age, while giant cell arteritis affects older patients, generally over 50 years of age.
Both Takayasu arteritis and giant cell arteritis affect large arteries, but the typical initial manifestations of the two diseases are also usually different. Patients with giant cell arteritis typically present with headaches affecting the temples, scalp tenderness, jaw pain and fatigue with chewing, shoulder or hip pain and stiffness, and/or sudden changes in vision (temporary or permanent blindness or partial vision loss). Patients with Takayasu arteritis usually do not have these symptoms but may have arm or leg pain with use, or chest pain, or be found to have no pulse in an arm or leg. However, many clinical findings may be similar between the two diseases, including the presence of constitutional symptoms (fatigue, fevers, chills, malaise, weight loss), muscle and joint pains, stroke-like symptoms, diminished or absent pulses, asymmetric blood pressures, and narrowed or blocked primary branches of the aorta found on imaging studies.
Giant cell arteritis is usually diagnosed by a temporal artery biopsy, whereas Takayasu arteritis is not, since the temporal artery is not classically affected in TAK. Diagnosis of Takayasu arteritis is usually made by imaging studies of arteries such as angiography.(Click the back button in your browser to go back to the FAQ page.)