A 28-year-old man from a leprosy-endemic area presents with a single hypopigmented, anaesthetic patch on his left forearm with loss of hair and anhidrosis over it. Skin smear from the lesion is negative. Slit-skin smear BI is 0. Which type of leprosy does he have?
- A Tuberculoid leprosy (TT) ✓
- B Indeterminate leprosy
- C Borderline tuberculoid (BT)
- D Lepromatous leprosy (LL)
Correct answer: A. Tuberculoid leprosy (TT)
Explanation
A single well-defined hypopigmented anaesthetic patch with complete loss of appendages and a bacillary index of zero is characteristic of tuberculoid (TT) leprosy. In TT leprosy, the immune response is strong (Th1-dominant), resulting in complete nerve and adnexal destruction within the single lesion. Indeterminate leprosy has a poorly defined patch without definite nerve thickening, while BT has 2-4 lesions with partial sensation.
Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.