Optic neuritis (ON) is the most common type of inflammatory, demyelinating disorder of the optic nerve, most often caused by multiple sclerosis (MS). However, alternative diagnoses should be considered and investigated thoroughly in the setting of other systemic symptoms. Optic neuritis is a rare manifestation of Lyme disease that typically improves with antibiotics.

Case Presentation:

A 50 year-old woman with history of breast cancer treated with mastectomy and chemotherapy in remission for ten years presented with a right-sided headache and right eye vision changes.

She was feeling well until three weeks prior to hospital admission in June when she developed fevers up to 103.1 °F, sweats, and a circular, slightly raised and pruritic rash on her neck, chest and on her right lower extremity. She was evaluated at an urgent care clinic where a rapid strep test was negative, and she was sent home without antibiotics. Over the next three days, fevers and rash resolved without treatment. Two weeks afterward, the patient developed a right-sided headache associated with right eye pain and intermittent blurry vision. She denied neck stiffness, joint pain, rash, or myalgias at that time. Outpatient ophthalmic evaluation revealed right optic disc edema and MRI of the brain showed enhancement along the right optic nerve. The patient had hiked in wooded areas in the Philadelphia region in the spring and summer months but was not aware of any mosquito or tick bites. Her allergies include an unknown allergy to oxytetracycline.