Hemophagocytic Lymphohistiocytosis in a Patient With Recent Initiation of HAART Coinfected With Mycobacterium avium Complex and Disseminated Histoplasmosis: Who Is the Culprit?Hilmers, David Carl MD, EE, MPHInfectious Diseases in Clinical Practice: November 2013 - Volume 21 - Issue 6 - p 389–391 doi: 10.1097/IPC.0b013e31827ce6d0 Case Report Abstract Author Information Abstract: Reactive hemophagocytic lymphohistiocytosis (HLH) is a disorder reported secondary to infectious, rheumatologic, neoplastic, and immunologic causes. Whereas increasingly recognized in patients infected with HIV, its diagnosis can be problematic in immunocompromised patients recently started on highly active antiretroviral therapy (HAART), undergoing immune reconstitution and encountering opportunistic infections. A young man recently diagnosed as human immunodeficiency virus (HIV) and started on HAART 3 weeks earlier presented with dyspnea and spiking fevers. Evaluation revealed HLH, disseminated Mycobacterium avium complex (MAC) and Histoplasma capsulatum. Prompt treatment of the precipitating conditions led to a reversal of his symptoms and a positive outcome. This is the first reported HLH case in a patient infected with HIV associated with M avium. The juxtaposition of HIV infection itself, reconstitution of the immune system with HAART, opportunistic infections, and HLH may create a confusing presentation with an inflammatory milieu whose pathophysiology is not well understood. Yet, HLH can be highly lethal if not promptly recognized and properly treated. From the Departments of Internal Medicine and Pediatrics, Baylor College of Medicine, Houston, TX. Correspondence to: David Carl Hilmers, MD, Department of Internal Medicine and Pediatrics, 1709 Dryden Rd, Suite 586B, Houston, TX 77030. E-mail: firstname.lastname@example.org. The author has no funding or conflicts of interest to disclose. © 2013 by Lippincott Williams & Wilkins.