72 y. o. gentleman comes to your office with a chief complaint of right foot pain. He thinks this started when he lifted something heavy the week before. The pain began as a burning discomfort in his right buttock. It then began to involve his leg. Currently, he only complains of exquisite tenderness on the bottom of his right foot. Exam reveals a negative straight and well leg sign. His sensory, motor and deep tendon reflex exams are intact. On the lateral aspect of the plantar surface of his foot is an area of grouped vesicles on an erythematous base. Required:
a. What would you do to further evaluate this patient’s complaint?
b. What is the mechanism for this patient’s pain?