Abstract
Background
Mpox increasingly presents with atypical genital lesions that often mimic common sexually transmitted infections (STIs) such as herpes simplex virus infection and chancroid, creating diagnostic confusion. This challenge is particularly pronounced in resource-limited settings, where confirmatory testing may be delayed.Case presentation
A 21-year-old Nigerian female presented with an acutely painful vulvar ulcer that developed 72 h after sexual intercourse. She was initially treated for genital herpes with acyclovir, but her condition worsened, with progressive vulvar oedema, severe pain, inguinal lymphadenopathy, and high-grade fever. A presumptive diagnosis of chancroid was made, and she was admitted and treated with intramuscular ceftriaxone, followed by oral erythromycin, ciprofloxacin, and diclofenac. Subsequently, she developed a generalized vesiculopustular rash involving the trunk, foot, forearm, palms, and soles. Laboratory testing confirmed mpox infection. She was managed with supportive care while completing antibiotic therapy, resulting in complete resolution of symptoms within two weeks.Conclusion
This case highlights the diagnostic dilemma posed by genital mpox, which can initially mimic herpes simplex virus infection or chancroid. Maintaining a high index of clinical suspicion is essential, particularly in patients with epidemiological risk factors and evolving systemic features. These findings are consistent with global reports of atypical, sexually associated mpox presentations.