Review Question - QID 109488

A 41-year-old man presents to the dermatologist for new rashes on both elbows. He states that he started noticing them last week and has never had any similar rashes before. They feel slightly itchy but are otherwise not bothersome. The patient tried topical hydrocortisone for 3 days with some resolution but when he stopped using the medication the rashes returned and worsened. He does not recall any unusual exposures to irritants or allergens. The patient has a past medical history of Hashimoto hypothyroidism for which he takes levothyroxine. He had his appendix taken out at age 17 for appendicitis. His family history is notable for type 1 diabetes mellitus in his father. At this visit, the patient’s temperature is 98.8°F (37.1°C), blood pressure is 127/80 mmHg, pulse is 76/min, and respirations are 13/min. Cardiopulmonary and abdominal exams are normal, and the skin exam is notable for the findings in Figure A. Which of the following is most likely to be found in this patient?