ENDOGENOUS METHEMOGLOBINEMIA ASSOCIATED WITH DIARRHEAL DISEASE IN INFANCY

Infantile diarrhea is sometimes associated with methemoglobinemia. To determine the significance of intestinal bacterial infection or overgr owth and other predisposing factors in this entity, we evaluated prosp ectively 45 consecutive patients who were admitted for gastroenteritis and methemoglobinemia between March 1980 and September 1992. All the patients were younger than 3 months of age. In 95% of them, methemoglo binemia occurred between the ages of 15 days to 2 months. The peak mea n methemoglobin concentration was 9.4% (range, 2.4-57%). Although stoo l cultures were positive in only 22% of the infants, the epidemiologic data strongly suggested a bacterial or viral etiology in our study po pulation: for 12 years, there was a significant decrease in the annual incidence of methemoglobinemia associated with diarrhea in parallel t o the decrease in infantile diarrhea due to known pathogens throughout the country in the same period. There was also a marked seasonal vari ation in the incidence of the disease, with two peaks in January and t he summer months when viral and bacterial infections, respectively, ar e prevalent. Failure to thrive and low admission-weight percentiles we re associated with methemoglobinemia in most of the patients and diarr hea lasting greater than or equal to 7 days in 22 (49%) patients. The blood pH and the degree of acidosis did not correlate with the severit y of methemoglobinemia, All the patients were formula fed. In the etio logy of methemoglobinemia in infants with enteritis, viral and bacteri al pathogens appear to play an important role by altering intestinal f lora. Breast feeding appears to protect against this entity.