Acquired Methemoglobinemia - A case report

This is a case report of 4 years old male child who presented with central cyanosis, involuntary movements, weakness of the trunk and respiratory distress. There was a history of accidental ingestion of 3 tablets of dapsone (100 mg each). Oxygen saturation was low in spite of high flow oxygen with blood drawn for investigations showing chocolate brown in color. Clinical diagnosis of methemoglobinemia was made .G6PD levels in blood were checked and child was started on intravenous methylene blue after drawing blood for methemoglobin levels. All his symptoms like cyanosis, involuntary movements, irritability disappeared drastically with two doses of methylene blue. Lab levels of methemoglobin came as 19.6. Child was discharged home on fourth day.Naranjo algorithm score was obtained which denotes a Probable Adverse Drug Reaction.