Severe Cutaneous Mpox: Necrotic Ulcer and Diffuse Rash in A Patient Living with Human Immunodeficiency Virus

Summary: Background: Mpox, is an emergent zoonotic viral infection transmitted through close contact with an infected individual, animal, or contaminated objects. Immunosuppressed patients may develop a necrotic lesion in addition to the diffuse rash. This case highlights the dermatopathology findings of Mpox infection in a patient living with HIV. Case Presentation: A 26-year-old male living with HIV, not on therapy, presented with a large necrotic ulcer in the right groin with heaped up borders and diffuse umbilicated vesicular rash over the entire body excluding mucosal surfaces. The groin ulcer began as a “pimple-like” lesion. For diagnosis, biopsies were obtained from the groin ulcer and another vesicle. Also, specimen was obtained for orthopox NAAT. Histopathology revealed epidermal ulceration, keratinocyte degeneration, and a mixed inflammatory infiltrate of lymphocytes, histiocytes, eosinophils, plasma cells, and neutrophils, which findings were consistent with orthopox infection. NAAT Mpox virus was positive. Infections with herpes viruses, Treponema pallidum, Klebsiella granulomatis, Hemophilus ducreii, chlamydiae were ruled out. The patient’s lesions healed within one week spontaneously. Conclusion: Mpox is a reemergent infection. Dermatopathology plays a critical role in its diagnosis, which is challenging due to rare viral inclusions and overlapping features. NAAT and communication are crucial for accurate diagnosis and management.