There are many cases of infantile beriberi (kakke) in Japan. In most instances the mother of the afflicted infant has beriberi. However, sometimes the mother is healthy (concealed beriberi). Ito observed such a case in which the mother did not have beriberi and called the condition "mother's milk intoxication." But he afterward changed this name to "breast milk intoxication" because he saw cases in babies who were nourished with the milk of wetnurses.
After many heated discussions at their annual meetings most of the Japanese pediatricians came to believe in the existence of concealed beriberi. There is no means of recognizing concealed beriberi, however, except by experiments on infants. So it was decided to allow the name "breast milk intoxication" with a prefix "so-called."
So-called breast milk intoxication is seen only in breast-fed infants. If the baby discontinues the breast milk that is causing the disturbance and takes another food
TANAKA T. SO-CALLED BREAST MILK INTOXICATION. Am J Dis Child. 1934;47(6):1286-1298. doi:10.1001/archpedi.1934.01960130110008