Unmasking Mycobacterium avium: two case reports of cutaneous lesions in HIV patients after initiation of an integrase inhibitor-based regimen

Mycobacterium avium complex (MAC) is the most common non-tuberculous mycobacteria (NTM) causing disease in immunosuppressed patients. People living with human immunodeficiency virus (PLHIV) typically present with disseminated infections characterized by non-specific constitutional symptoms such as fever, night sweats, and weight loss. Cutaneous lesions in disseminated MAC are rare and include panniculitis, granulomas, pustules, papules, nodules, abscesses and ulcerations, and ulcers. Here, we present two HIV patients who developed a disseminated MAC infection with skin lesions. A 40-year-old woman with a 10-year history of untreated HIV infection and a 47-year-old woman recently diagnosed with HIV both presented with constitutional symptoms. After routine screening for opportunistic infections and exclusion of active infection, they were started on antiretroviral therapy (ART) with tenofovir, lamivudine, and dolutegravir. One month later, both presented inflammatory skin lesions that evolved into ulcers. Case 1 presented with painful nodules of variable size on the upper and lower extremities that subsequently suppurated and ulcerated. Case 2 presented with erythematous-violaceous nodules on the trunk and limbs that progressed to ulceration with irregular borders, well defined, infiltrated, with necrotic background and fine perilesional desquamation. The secretion of the lesions was analyzed in both cases. Ziehl-Neelsen stain showed the presence of acid-fast bacilli only in case 1, while the GeneXpert MTB/RIF assay was negative in both cases. The biopsy of case 2 documented panniculitis. Non-pigmented colony growth was observed after 42 and 38 days of incubation, respectively. PCR restriction enzyme pattern analysis demonstrated the presence of MAC in both cases. Clarithromycin and ethambutol were started in both cases, and clofazimine was added in case 1, resulting in a satisfactory clinical course in both patients, as evidenced by the healing of the ulcers. These cases of disseminated MAC infection highlight that unmasking immune reconstitution inflammatory syndrome can present with severe cutaneous lesions shortly after the initiation of modern ART. Our report underscores the need for a high index of suspicion for NTM infections in patients with advanced HIV who develop new inflammatory syndromes, particularly in resource-limited settings where diagnostic delays for mycobacterial diseases are common.