Abstract
Human immunodeficiency virus (HIV) and syphilis are two sexually transmitted diseases that continue to pose significant public health challenges globally. HIV and syphilis can be seen together; individuals with one of these infections are at risk of developing the other. Sharing common risk factors such as sexual transmission or intravenous drug use makes their coincidence likely. Syphilis, an infection caused by a spirochaete (Treponema pallidum), is a great mimicker and can present with a wide variety of clinical manifestations. Syphilis can cause various neurological symptoms including complete oculomotor nerve palsy; however, it is not a common manifestation. Here, we report for the first time a case of persistent incomplete oculomotor nerve palsy with pupillary involvement caused by the involvement of the inferior division of the oculomotor nerve, secondary to HIV and syphilis co-infection.