Ocular syphilis masquerading as bilateral peripheral ulcerative keratitis

Ocular syphilis has varied manifestations in the eye. Peripheral ulcerative keratitis (PUK) is a crescent-shaped ulcer involving the peripheral cornea and associated with thinning. PUK is caused by both autoimmune and infectious diseases, such as rheumatoid arthritis, tuberculosis, and herpes. Here, we report a rare case of bilateral PUK caused by syphilis. A 55-year-old man presented with recurrent pain and redness in both eyes for 2 months. The cornea of both eyes had bilateral peripheral crescent-shaped ulcers suggestive of PUK. The patient was started on topical steroids elsewhere, but the lesion was not showing any signs of healing. A series of investigations were performed, with positive venereal disease research laboratory and fluorescent treponemal antibody absorption tests. The patient was then started on systemic penicillin, as well as topical steroids. The response to the treatment was good and the ulcer began to heal. PUK as the presenting feature of acquired syphilis is a rare scenario. Such infective causes should be managed with systemic antimicrobials for optimal outcomes.