Mimics of Mpox: Considerations for the emergency medicine clinician

Introduction: Mpox, formerly known as monkeypox, is a public health emergency most commonly presenting with a painful rash and several systemic findings. However, there are several conditions that may mimic its presentation. Objective: This narrative review provides a focused overview of mpox mimics for emergency clinicians. Discussion: Mpox is a global health emergency. The disease is primarily spread through contact, followed by the development of a centrifugally-spread rash that evolves from macules to papules to vesicles to pustules. This is often associated with lymphadenopathy and fever. As the rash is one of the most common presenting signs of the infection, patients mpox may present to the emergency department (ED) for further evaluation. There are a variety of mimics of mpox, including smallpox, varicella, primary and secondary syphilis, acute retroviral syndrome, and genital herpes simplex virus. Conclusion: Knowledge of mpox and its mimics is vital for emergency clinicians to differentiate these conditions and ensure appropriate diagnosis and management.