Red Blood Cell Exchange for Naphthalene-Induced Methemoglobinemia in a Child With Glucose-6-Phosphate Dehydrogenase Deficiency: A Case Report.

Naphthalene toxicity is a rare but serious cause of methemoglobinemia and hemolysis, particularly in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency, in whom methylene blue is contraindicated. We present a case of a 6-year-old girl with a family history of G6PD deficiency who developed cyanosis, jaundice, dark urine, and an oxygen saturation of 50% after ingesting a mothball. Laboratory findings confirmed hemolytic anemia with suspected methemoglobinemia. Methylene blue was avoided, and initial treatment with high-flow oxygen, ascorbic acid, and N-acetylcysteine failed to improve her condition. Red blood cell exchange (RCE) was performed, leading to rapid normalization of oxygen saturation and resolution of hemolysis. G6PD deficiency was later confirmed by enzyme assay. We concluded that in G6PD-deficient children with naphthalene-induced methemoglobinemia, RCE provides an effective alternative to methylene blue, resulting in rapid recovery.