Occurrence of methemoglobinemia due to COVID-19: a case report

Methemoglobinemia (MetHb) is a rare, life-threatening condition that occurs when the body is exposed to oxidative stress. It is typically corrected through the glucose-6-phosphate dehydrogenase (G6PD)-dependent shunt. G6PD deficiency is the most common enzymatic deficiency worldwide. This genetic disorder makes patients susceptible to oxidative stress and reduces the expected life span of erythrocytes (red blood cells (RBCs)) among other cells. G6PD deficiency is asymptomatic in most cases unless exogenous stressors are introduced, whether they are dietary, iatrogenic, or infections, such as the highly transmissible serotype of coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We report a case of an 11-year-old male with known insulin-dependent diabetes mellitus (IDDM) and glucose-6-phosphate dehydrogenase (G6PD) deficiency, who was found to develop methemoglobinemia after being infected by the SARS-CoV-2 virus. The direct effects of COVID-19 on children were reported to be lower than on adults. However, the effects of COVID-19 on children with comorbidities, such as G6PD deficiency in our patient, are understood only to a minimal extent. Moreover, identifying cases of G6PD deficiency prior to initiating treatment with methylene blue, hydroxychloroquine (HCQ), or other contraindicated agents is essential to prevent further deterioration in symptoms.