American Board of Internal Medicine (ABIM) Certification Practice Exam

Which of the following criteria is NOT effective for distinguishing giant cell arteritis from other vasculitides?

1. Age >50

2. Localized new-onset headache

3. Erythrocyte sedimentation rate >50 mm/h

4. Presence of skin rash

The correct answer is: Presence of skin rash

Giant cell arteritis (GCA), also known as temporal arteritis, is a specific type of vasculitis that primarily affects older adults and is characterized by inflammation of the large and medium-sized arteries. The criterion of the presence of a skin rash is not effective for distinguishing GCA from other forms of vasculitis. While some types of vasculitis can present with skin manifestations, such as cutaneous symptoms seen in conditions like polyarteritis nodosa or systemic lupus erythematosus, GCA typically does not have skin involvement as a primary feature. Instead, its hallmark symptoms include headache, visual disturbances, and other systemic signs. In contrast, the other criteria are more closely linked with GCA. Age greater than 50 is a significant risk factor since GCA predominantly occurs in this age group. A localized new-onset headache is often one of the most common presenting symptoms and can be a key indicator of GCA. An elevated erythrocyte sedimentation rate (ESR) over 50 mm/h indicates significant inflammation and is commonly observed in GCA patients, reflecting the systemic inflammatory process at play. Thus, recognizing the presence of a skin rash does not help in differentiating GCA from other vas