Lepra type II reaction is also called erythema nodosum leprosum (ENL). It affects those with with borderline lepromatous or lepromatous leprosy and is a humoral (antibody-antigen) reaction to immune complexes. Repeated episodes tend to occur later in treatment than the type I reaction, usually after several years.
ENL presents as painful red nodules (lumps), which can blister or ulcerate, accompanied by fever, malaise, joint pain, nerve pain, eye disease and involvement of other organs. Treatment may include clofazimine, thalidomide, corticosteroids, colchicine, ciclosporin or tumour necrosis factor antagonists.