Progressive chronic calvarial osteomyelitis in rhino-orbital mucormycosis associated with COVID-19

We describe two cases of extensive indolent calvarial osteomyelitis after rhino-orbital-mucormycosis in diabetic patients previously diagnosed with COVID-19. Both patients presented with acute rhino-orbital symptoms about one month after being diagnosed with COVID-19. Treatment with intravenous liposomal Amphotericin B and prompt radical surgical debridement was instituted, but calvarial osteomyelitis ensued and persisted chronically despite maintenance of antifungal therapy and partial debridement of necrotic calvarial bone. The patients were discharged to continue antifungal therapy on a day-hospital regime. After more than 8 months of treatment, they remain with radiological signs of osteomyelitis but with no symptoms or intracranial extension of the infection. Calvarial indolent osteomyelitis secondary to mucormycosis is extremely rare, and little is known regarding its treatment. We believe it can be controlled with medical treatment and partial bony debridement although more studies are necessary to better define therapy.