Version July 2025
| Paucibacillary leprosy | Multibacillary leprosy | ||||
| Tuberculoid (TT) | Borderline tuberculoid (BT) | Mid-borderline (BB) | Borderline lepromatous (BL) | Lepromatous (LL) | |
| Clinical features | |||||
| Dermatologic findings | One or two macular hypopigmented or erythematous lesions, with borders that are well-defined, often raised | One to five infiltrated erythematous plaques, or one large annular lesion | More than six infiltrated plaques with 'Swiss cheese' appearance | More than six annular plaques |
|
| Symmetry of distribution | Asymmetric | Asymmetric | Asymmetric | Symmetric | Symmetric |
| Presence or absence of anesthesia | Anesthetic | Anesthetic | May or may not be anesthetic | May or may not be anesthetic | No anesthesia |
| Risk for immunologic reaction | (None) | Type 1 reaction | Type 1 reaction | Type 1 or type 2 reaction | Type 2 reaction |
| Biopsy findings | |||||
| Histopathology |
| Mix of tuberculoid and lepromatous findings. BT: More likely to observe well-formed granulomas. BB or BL: More likely to observe macrophages. | Sheets of foamy macrophages | ||
| Acid-fast bacilli | None detected | Few or none detected | Many | Many | Many (globi) |
The Ridley-Jopling classification is based on the cutaneous, neurologic, biopsy findings and number of acid fast bacilli present in the dermis, all of which correlate with the immunological capability of the host.
Indeterminate leprosy usually manifests with hypopigmented patches with nonspecific perineural infiltrates in which rare acid-fast bacilli can be demonstrated. It often occurs in children, and may heal spontaneously. The indeterminate classification should be used only if the biopsy demonstrates definitive evidence of leprosy (both perineural inflammation and acid-fast bacilli).