is this an allergie??

my grandaughter had a walnut cookie last night, only had three bites and refused to eat anymore.  she developed a fever, vomiting, diarrrhea and severe rash around the neck and shoulders and also on her upper torso, the rash was flat and very itchy. the walnut cookie was also made with powdered eggs.  her mother went and bought her benadryl to take and it stopped the symptoms.  i used to be in the medical field, looked at pics of my granddaughter and it sure looked like an allergic reaction.  all symptons are gone now and she is fine today. is this an allergic reaction and could she also start reacting to other peanut products?????? thank you grandma suzie

[Super_sally888]

Waltnuts and peanuts are not the same.  

This definitely sounds like allergy to something in the cookies.  Either the walnuts, or the eggs, or something else.

Has she had walnuts before?  Does she usually eat eggs with no problem.

If this is the first time forwalnuts, I would be very cautious about giving them to her again.

Her mother could always request allergy testing for this.