Based on presence of any one of the following Cardinal signs.
| Sr. No | Cardinal Signs of Leprosy | Method of Eliciting |
| 1 | Hypopigmented or reddish Skin lesion(s) with definite loss of sensation |
Anaesthesia on the patch to be elicited by testing for touch, pain and temp. sensation |
| 2 | Thickening of peripheral nerves with loss of sensation and weakness of the muscles of the hands, feet or face | Examination of peripheral nerves e.g 1) Greater Auricular 2) Radial 3) Ulnar 4) Median 5) Lateral Popliteal 6) Posterior Tibial etc. |
| 3 | Demonstration of Mycobacterium Leprae (M.leprae) in the lesions | Acid fast staining and examination Under oil immersion microscope |
Pre–requisites of Good Clinical Examination
- Assurance & counseling of patients and/or family.
- Essentially in good daylight.
- Exam. of whole body with courtesy & respect to patient's privacy.
- Examination of female patient as far as possible by a female doctor or at least in the presence of one female.
- The location of skin lesions be marked on a simple body outline.
- One or few typical skin lesions should be tested for loss of sensation.
- The main peripheral nerve trunks should be palpated to certain any thickening and tenderness.
- Eyes, hands and feet should be examined.
| Clinical Manifestation | PB (Pauci–Bacilli) | MB (Multi Bacillary) |
| Skin Lesion | Upto 5 lesion | 6 and above |
| Nerve involvement | No nerve involvement or only one nerve involvement | more than one nerve trunk involvement |
