Abstract
Methemoglobinemia is a rare and often neglected cause of cyanosis in pediatric population. It can result from either congenital conditions or acquired processes from exposure to sub-stances that oxidizes hemoglobin. Phenazopyridine, a pain reliever for urinary tract symptoms, widely used, is one of those substances. The methemoglobinemia diagnosis can be a clinical challenge, and this hypothesis must be considered in patients with central cyanosis and persis-tent low saturation despite oxygen administration. Severe cases should be treated with meth-ylene blue, removal of the causal factor and aggressive oxygen therapy. This present case re-ports the diagnosis of a pediatric patient with methemoglobinemia induced by intentional in-toxication with phenazopyridine, that received fast and appropriate treatment, with satisfacto-ry outcome.