Race for the Case

A 74-year-old Caucasian male with a history of squamous cell carcinoma, hypertension, and hyperlipidemia presented with a solitary lesion over the left lateral lower leg. On physical exam, a single erythematous infiltrative plaque with an anesthetic center was noted. Decreased sensation to touch was present on the plantar surface of the left foot. He denied pain, itching, fever, cough, or chills. The patient reported Florida residence of over 20 years. He denied recent trauma, international travel, or animal exposure. Well-formed granulomas throughout the dermis and perineurally were noted on histopathology. Fite and AFB were negative for organisms. The specimen was sent for PCR and slit-skin smear microscopic evaluation.

1. What is the diagnosis and causative agent?
2. What is the name of the classification system which polarizes the five subtypes of this disease based on a patient’s cell-mediated immunity? Which would this patient be classified as?
3. What is the organism’s ideal temperature for growth?
4. What is the mode of transmission?
5. What HLA subtypes are associated with this condition?
6. Which antibody is associated with reactions and impaired nerve function?
7. For how many years after treatment completion should patients be screened?