Table 1. World Health Organization System and Ridley-Joplin Classification and Type of Reaction.
| WHO | Paucibacillary | Multibacillary | |||
| Ridley-Joplina | TT | BT | BB | BLb | LL |
| Type 1 Reaction | No | Yes | Yes | Yes | No |
| Type 2 Reaction | No | No | No | Yes | Yes |
WHO classification is used for operational purposes in the field and it is based on the number of skin lesions; Ridley-Joplin classification is an immunopathological and clinical classification.
Adapted from [5].
a
Ridley-Joplin classification: tuberculoid (TT); borderline tuberculoid (BT); borderline borderline (BB); borderline lepromatous (BL); and lepromatous (LL).
b
Patients with BL can develop both types of reactions.