Abstract
The prevalence and incidence of food protein-induced enterocolitis syndrome (FPIES)
are clearly not known; its onset before first feeding at birth especially has been
rarely reported. A female newborn was referred to our institution due to blood-stained
diarrhea before her first feeding at birth. Examination of the stool with Wright-Giemsa
staining on day 6 revealed numerous fecal eosinophils, including Charcot-Leyden crystals.
Lymphocyte stimulation test (LST) against cow's milk protein also showed positive
values on day 12. The hematochezia resolved immediately after starting intravenous
nutrition. She was fed with breast milk and extensively hydrolyzed formula and discharged
from hospital on day 49. FPIES was diagnosed based on these symptoms and data. Our
case was thought to have acquired allergic enterocolitis after sensitization in her
fetal period, which caused severe FPIES triggered by the first intake of cow's milk
soon after birth. The patient with FPIES presents atypical clinical findings, which
is likely to cause misdiagnosis and delay of appropriate treatment. Heightened awareness
and increased attention may be necessary to diagnose FPIES, even soon after birth.
Evaluating fecal eosinophils and LST, which may be difficult to perform in every clinical
hospital, is thought to be useful for the detection of FPIES without oral food challenge.
Keywords
Food protein-induced enterocolitis syndrome - hematochezia - fecal eosinophils - Charcot-Leyden
crystals - lymphocyte stimulation test