For parents who have children with food allergies.?

I have a 2 year old daughter who rashes out if she eats peanuts or eggs. And last night I bought cookies, after checking the ingredients to rule out peanuts and eggs. Shortly after eating them, her mouth swelled up!! I watched her closely until the swelling went down. There was never a rash or any other reaction. We have an apt with an allergy doctor this week. My question is… Parents with children with food allergies… What kind of test(s) do they run for food allergies? Will they do it at our first visit or have us come back? And any other advice you can give me.
Thanks in advance!
We don’t have an epi-pen yet. I was told it had to be prescribed to her before we could get one.

What’s the difference between an allergy and a reaction to something?

Last night I had to take my little boy to the emergency room. The nurse asked if he had any allergies. I told her panadol makes him throw up. She said that’s not an allergy, just a reaction.

Isn’t an allergy just the bodies way of reacting to something that doesn’t agree with it?

Thank you in advance for your answers.

Why do allergy shots reduce symptoms, but not being constantly exposed to another type of allergen?

First of all I’m taking allergy shots, but I’m confused because it doesn’t make sense to me that injecting an allergen can make your body more immune to an allergen whereas constant exposure to allergens (non shot-related) does not seem to be helpful at all.

I’ve heard people say that their pet allergies “went away” after living with a new pet or something, but mine have never done this.

So in a nutshell, why does injecting an allergen through allergy shots help with immunity, while having other types of exposure to allergens make symptoms worse? You’d think if I’m constantly exposed to dust mites, then it’d build up an immunity. I’ve read all kinds of stuff, but I don’t seem to be able to find an answer.