Cutaneous Histoplasmosis in Advanced HIV: A Case of Systemic Fungal Dissemination

Disseminated histoplasmosis is a severe opportunistic infection in patients with human immunodeficiency virus (HIV) infection, particularly in those with CD4 lymphocyte counts of ≤50 cells/µL. Cutaneous involvement usually occurs as part of disseminated disease and, in some cases, may represent the first manifestation of systemic involvement. Cutaneous manifestations are highly variable, and these lesions are commonly associated with constitutional symptoms and pulmonary involvement. We present the case of a 53-year-old man with a history of HIV infection clinical stage C3, miliary tuberculosis with incomplete treatment, and poor therapeutic adherence. He developed a pruritic dermatosis characterized by erythematous lesions associated with fever, odynophagia, asthenia, and adynamia. At admission, generalized and symmetrical dermatosis was observed, consisting of innumerable erythematous-violaceous papules and macules coalescing into plaques, in addition to palmoplantar lesions with a collarette scale resembling the "Biett sign." Histopathological examination demonstrated histiocytes filled with multiple intra- and extracellular yeast-like structures consistent with Histoplasma capsulatum. HIV viral load was reported at 8,070 copies/mL and CD4 T-lymphocyte count at 46 cells/µL. Based on these findings, a diagnosis of disseminated cutaneous histoplasmosis was established. During hospitalization, the patient received liposomal amphotericin B, and upon discharge, antiretroviral therapy (ART) was initiated, resulting in favorable clinical evolution and the improvement of the cutaneous lesions during outpatient follow-up. This case illustrates the diagnostic complexity of disseminated cutaneous histoplasmosis in patients with advanced immunosuppression and highlights the value of skin biopsy and early histopathological identification in establishing a timely diagnosis and initiating prompt antifungal treatment.