The term "lepra reaction," in its broad sense, includes any sudden unusual, or acute reactive episode that occurs unpredictably within the common, chronic course of leprosy. Some authors restrict the term to the erythema nodosum type of reaction and then speak of "erythema nodosum leprosum."
The Committee on Classification of the International Congress of Leprosy,1 in a meeting held in Madrid in 1954, stated that reactional lepromatous leprosy has 2 forms; namely, (1) lepra reactions which consist essentially of aggravation of preexisting skin lesions, usually with fever and extension of lepromatous process, and (2) erythema nodosum leprosum, which is char
CANIZARES O, COSTELLO M, GIGLI I. Erythema Nodosum Type of Lepra ReactionGeneral Considerations and Report of Three Cases Treated with Long-Term Adrenocorticosteroid Therapy. Arch Dermatol. 1962;85(1):29–40. doi:10.1001/archderm.1962.01590010035005