Acute and chronic FPIES have been well characterized in children.
Few data still exist on neonatal FPIES (N-FPIES) which may involve a distinct pathophysiology and is characterized by specific clinical features which make challenging the diagnosis.
Although risk factors remain poorly understood, scientific evidence suggests that gut microbiota alterations may play an important role in the development of FPIES.
In regard to N-FPIES clinical presentation, there is evidence of two distinct phenotypes, according to the presence or absence of bloody stools.
Although N-FPIES shares symptom similarities with infant acute FPIES, it may not fully meet the diagnostic criteria at onset.
The present review highlights our current understanding of N-FPIES, focusing on risk factors, including microbiota alterations, clinical characteristics and differential diagnosis with other neonatal medical and surgical conditions.
In addition, current treatment strategies for both term and preterm infants are also described and commented.
Refining diagnostic criteria for N-FPIES represents a clinical priority to help physicians in approaching this challenging condition. Last, but not least, larger clinical trials are needed to optimize treatment practices in term and preterm newborns with FPIES.