|Major criterion||Minor criteria|
|Vomiting in the 1–4 h period after ingestion of the suspect food and the absence of classic IgE-mediated allergic skin or respiratory symptoms||
3. Diarrhea in 5–10 h after food ingestion
6. Increased neutrophil count of at least 1500 neutrophils above the baseline count
The OFC will be considered diagnostic of FPIES, i.e. positive, if the major criterion is met with at least two minor criteria.
However, we would suggest two important caveats to these criteria:
1) with the rapid use of ondansetron, many of the minor criteria, such as repetitive vomiting, pallor and lethargy may be averted; and
2) not all facilities performing challenges have the ability to perform neutrophil counts in a timely manner.
Therefore, the treating physician may decide that a challenge be considered diagnostic in some instances even if only the major criterion was met. However, in challenges performed for research purposes, stringent criteria for challenge positivity should be adhered to.