Presumptive Rhino-Orbital Mucormycosis Secondary to Corticosteroid Therapy in a Diabetic Patient With COVID-19 Infection

The coronavirus disease 2019 (COVID-19) pandemic has led to the widespread use of steroids as a life-saving measure. In patients with preexisting diabetes, the therapeutic use of steroids coupled with poorly controlled sugar has led to a surge of mucormycosis. We report a rare case of orbital apex syndrome secondary to mucormycosis post-COVID-19. A 43-year-old female with poorly controlled diabetes mellitus presented with right eye complete ptosis one week post-recovery from COVID-19 infection. During COVID-19 hospitalization, she received a course of dexamethasone. The visual acuity of the right eye was 6/60. She had complete ophthalmoplegia and diplopia in all gazes. There was a positive relative afferent pupillary defect (RAPD) and reduced optic nerve function test in the right eye. MRI showed right ethmoid sinusitis with possible extension to the right orbit and the presence of right perineural optic nerve enhancement. The nasal scope revealed fungal-like thick mucopurulent discharge at the middle meatus. She was clinically diagnosed with rhino-orbital mucormycosis and was started on antifungal for six weeks. Her overall condition improved with 6/6 visual acuity and minimum residual ophthalmoplegia. In conclusion, corticosteroid treatment for COVID-19 infection in diabetic patients causes poor glycemic control and immunosuppression that can lead to secondary infections such as rhino-orbital mucormycosis.