Disseminated Mycobacterium haemophilum infection in an immunocompromised host: A complex case with immune reconstitution inflammatory syndrome (IRIS) manifestation

Abstract Background Mycobacterium haemophilum is a rare but significant opportunistic pathogen known to cause infections in immunocompromised individuals. Despite its low prevalence, disseminated infections with this organism can present diagnostic and therapeutic challenges, particularly in hosts with compromised immune systems. The phenomenon of Immune Reconstitution Inflammatory Syndrome (IRIS) further complicates the clinical course and management of such cases. Case Presentation : A 39-year-old male patient with a medical history of T-cell acute lymphoblastic leukaemia (T-ALL) who underwent a matched unrelated donor haematopoietic stem cell transplantation four years prior presented with fever and rash affecting all four limbs and the back. Subsequent evaluation confirmed a diagnosis of cutaneous Mycobacterium haemophilum infection, which was found to have disseminated to multiple organ systems including the lungs, gastrointestinal tract, and nasal turbinate. Treatment initiation resulted in immune reconstitution inflammatory syndrome (IRIS), posing challenges in managing the infection in the context of heightened immune response post-reconstitution. This case highlights the complexities involved in managing disseminated mycobacterial infections with IRIS following immune reconstitution. Conclusion This case highlights the diagnostic dilemmas and therapeutic considerations in managing disseminated Mycobacterium Haemophilum infection in immunocompromised hosts. The manifestation of IRIS further complicates the clinical course, necessitating a multidisciplinary approach to optimize patient outcomes. Our experience underscores the importance of early recognition, tailored antimicrobial therapy, and meticulous monitoring in managing such cases, with implications for clinicians caring for immunocompromised patients.