A 56-year-old woman presents to the ED complaining of blisters in her mouth. The first one appeared two days earlier. Now there are multiple blisters, although they are not painful. She hasn't noticed her gums bleeding or any other blisters or rashes on her body.
She does report some easy bruising on her arm, and reports that she recently was admitted to the hospital for chest pain, and had a cardiac catheterization.
No intervention was done, but she was told to continue her pre-admission medications, including lisinopril, atorvastatin, and metoprolol. She also started taking clopidogrel during this past admission.
Her vital signs are normal, and her physical exam is remarkable for the oral blisters pictured here and some ecchymosis on the left arm. No petechiae are seen.
What tests should be ordered, and what is the most likely diagnosis? See p. 39.