Environmentally-induced methemoglobinemia in an infant.
Acquired methemoglobinemia results from the exposure to various chemicals and drugs able to oxidize hemoglobin at a rate exceeding the normal enzymatic capacity for hemoglobin reduction. Levels of methemoglobin exceeding 60-70% may be associated with coma and death. We describe a case of complete, uneventful recovery involving a 10 week-old infant who presented to the Emergency Department with profound sudden onset of cyanosis, irritability, metabolic acidosis, and a lethal methemoglobin level of 71.4%. Intravenous administration of 12 mg methylene blue resulted in immediate resolution of the cyanosis and reduction of measured methemoglobin to 1.3%. The carboxyhemoglobin was negative. Sodium bicarbonate successfully corrected the acidosis. RBC reductase measurement was within normal limits, ruling out congenital methemoglobinemia. Family history revealed a wood-burning stove which emitted pine tar fumes as the potential environmental methemoglobin-producing source. The infant's cradle was situated five feet from the stove. The infant was discharged on day three of hospitalization with a methemoglobin level of 0.2%.
Dean
B S
BS
Pittsburgh Poison Center, Children's Hospital of Pittsburgh, Pennsylvania 15213-2583.
Lopez
G
G
Krenzelok
E P
EP
D003407:Creosote / Q000506:poisoning*; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D007223:Infant; D008708:Methemoglobinemia / Q000139:chemically induced* / Q000188:drug therapy; D012906:Smoke / Q000009:adverse effects*
D012906:Smoke; D003407:Creosote