Abstract
BACKGROUND: Monkeypox (MPX) is a zoonotic infection that is endemic in Western and Central Africa along the Congo River basin. It has a high case fatality rate especially in younger age groups. It belongs to the virus family orthopoxvirus like smallpox. It is transmitted from wild animals to humans but human to human transmission has been established. It is often a self-limited infection in endemic regions. Recently, attention has been given to MPX with the spread of infection to Europe and the United States of America (USA). There is currently sporadic infection of MPX in the USA especially amongst men who have sex with men (MSM). It is a serious life-threatening infection in human immunodeficiency virus/acquired immunodeficiency syndrome co-infected individuals especially those who are treatment naïve with severe immunosuppression. CASE SUMMARY: We report a 38-year old man who presented with rectal pain, and anal, torso, and facial rash. Abdominal computed tomography scan showed a near obstructive rectal mass with peri-anal fistula. MPX was positive. He was started on tecovirimat (TPOXX) and HAART therapy. Additional treatment provided included vaccinia immunoglobulin following his clinical deterioration. CONCLUSION: This case highlights a rare presentation of MPX with peri-anal fistula and near obstructive rectal mass, and the significance of MPX as a differential diagnosis in proctitis in MSM in addition to other sexually transmitted infection like gonorrhea and chlamydia.