ABSTRACT
In a patient of leprosy, skin or nerve lesions may suddenly flare up in a state of immunological reaction, and the resultant systemic inflammatory complications such as severe neuritis, high fever, episcleritis, epididymo-orchitis, sudden onset of neurological impairment such as foot drop and wrist drop usually need emergency medical and occasionally surgical measures. These episodes are called lepra reactions. In lepra reactions, the infected nerves and surrounding tissues are damaged as the host mounts an immune response to bacterial antigens. Leprosy reactions play a significant role in the morbidity associated with the disease. Reactions are responsible for most of the permanent nerve damage, deformity, disability, and death in leprosy. Two major types of reactions are recognized in leprosy. Type 1 lepra reaction is a delayed-type hypersensitivity reaction (type IV hypersensitivity reaction); type 2 lepra reaction, erythema nodosum leprosum, is thought to be an immune complex disorder. The reactions can occur during the natural course of untreated disease, during therapy, or after completion of multidrug therapy. These reactions must be managed as emergencies with oral corticosteroids, thalidomide, or other alternative therapies along with continuation of multidrug therapy.
