Type 2 leprosy reaction presenting as a monoarthritis post multidrug therapy.

Type 2 leprosy reaction, or (ENL), involves a complex interaction between the host's immune system and . It may occur before, during, or after treatment and have a variable clinical presentation involving different body systems, such as skin, osteoarticular, kidneys, and others. Thus, the differential diagnosis, depending on its clinical presentation, can be broad and challenging. The authors report a case of a severe monoarthritis during a type 2 reaction after the multidrug therapy (MDT) was discharged and the investigation of the differential diagnoses.