Methemoglobinemia and Consumption of Vegetables in Infants

Objective. To assess clinical and epide- miologic data of 7 infants diagnosed with acquired met- hemoglobinemia at the pediatric emergency department between 1993 and 1998. All cases were attributed to the consumption of mixed vegetables. Methods. Medical records were reviewed to collect anamnestic data; history of food ingestion; and results of physical examination, pulse oximetry, gasometry, cooximetry, urinalysis, and outcome. Local health author- ities provided information on nitrate concentration in running water and in vegetables of common consump- tion in the area. Results. The mean age of the patients was 8.14 months (range: 7-13). None of the infants was under- nourished, had diarrhea, or was given any drug. Drink- ing water showed a nitrate concentration of 3 to 6 ppm. All were fed homemade puree of mixed vegetables, pre- pared in advance and kept in the refrigerator for 12 to 27 hours. Silver beets were a common ingredient. No case showed metabolic acidosis. Methemoglobin level ranged between 10% and 58%. Three cases had nitrituria. Silver beets in our area were the vegetables with the highest nitrate concentration (mean: 3200 mg/kg). Conclusions. Consumption of silver beets and incor- rect storage of homemade purees of mixed vegetables were potential causes of methemoglobinemia in this se- ries. The disease may occur in children older than 6 months of age. Nitrituria in a cyanotic infant may suggest the diagnosis of methemoglobinemia. Pediatrics 2001; 107:1024 -1028; methemoglobinemia, nitrates, nitrites, food analysis, infant food, food preservation.