RESUMO
Immune reconstitution syndrome (IRIS) is an uncommon complication seen in patients living with human immunodeficiency virus (HIV) characterized by the decline in a pre-existing condition or a new diagnosis of a masked disease. It is associated with a significant inflammatory component that occurs after starting antiretrovirals, being most frequent in those with severe immunosuppression. Thereby, different types of opportunistic diseases such as non-tuberculous mycobacteria are more frequent in this group of patients, especially those with low lymphocyte counts of below 50 cells/µL. Here, we present the case of an HIV-positive patient who developed lymphadenitis caused by Mycobacterium intracellulare as an unmasked IRIS after initiating treatment for HIV.