Review Question - QID 216609

A 55-year-old man presents to his primary care physician with fatigue, malaise, and a painful rash. The patient states that his symptoms have been worsening over the past week. He also has experienced abdominal pain and diarrhea. He has a medical history of obesity and smokes regularly. His temperature is 97.5°F (36.4°C), blood pressure is 142/82 mmHg, pulse is 85/min, respirations are 15/min, and oxygen saturation is 98% on room air. Physical exam is notable for an erythematous rash with papules and plaques on the patient's face, torso, and extremities. He states that the rash is painful. A fingerstick blood glucose is unable to accurately read his blood glucose and gives a reading of > 500 mg/dL. Which of the following is the most likely underlying pathophysiology of this patient’s condition?