Plasmodium vivax malaria, an endemic parasitic disease in several regions worldwide, represents an important public health problem, especially in pediatric populations. Glucose-6-phosphate dehydrogenase (G6PD) deficiency, a common genetic condition, can worsen the clinical course of malaria, making individuals more susceptible to hemolytic complications. Methemoglobinemia, characterized by hemoglobin oxidation, is a potentially severe complication that may develop in patients with malaria, particularly in those with G6PD deficiency. This study aimed to investigate the association between P. vivax malaria, G6PD deficiency and methemoglobinemia in children, evaluating the impact of this association on disease prognosis. To analyze the association between P. vivax malaria, G6PD deficiency and methemoglobinemia in a pediatric patient and to evaluate its impact on disease prognosis. Case report, a qualitative approach that aims at the detailed analysis of a specific phenomenon within its real-life context. This report describes the case of a 6-year-old child with P. vivax malaria associated with G6PD deficiency and progression to methemoglobinemia, a rare and challenging condition in endemic areas. During treatment with primaquine, the patient developed progressive anemia, cyanosis and persistent hypoxemia, with methemoglobin level of 23%. Red blood cell transfusion and ventilatory support were essential for clinical stabilization, since methylene blue is contraindicated in patients with G6PD deficiency, and supportive management with close monitoring was performed. This case reinforces the importance of screening for G6PD deficiency before using oxidant antimalarials in endemic regions, as well as vigilance for signs of hemolysis and methemoglobinemia in children with P. vivax malaria. Early identification of deficiency, appropriate therapeutic choice and careful clinical follow-up are crucial to reduce complications and mortality, contributing to safe protocols for managing complex pediatric cases.
Nascimento et al. (Sun,) studied this question.