Just curious if anyone might have insight on this - I have never had any issues with food allergies..?!

>It could very well be an allergic reaction to eggs. DO NOT eat any more eggs. See your doctor and have an allergist determine if you are allergic. Be careful, in the mean time, to read all food labels and avoid anything with eggs until you know for sure whether or not you are allergic. Eggs are one of the top 8 known allergens recognized by FDA.

first of all, food allergies rarely involve stomach upset.
Second, there is no difference between a brown egg and a white egg, nutritionally, flavor or otherwise.
The color of the shell has to do with the breed of hen that layed it. Nothing else.
Your symptoms could be a touch of food born illness.
How old were the boiled eggs?
Did you use mayo?
If both of those things were okay, I would say it is in your head.
Many people view brown eggs as less than top quality.
The fact is, they are the same as white eggs in every way except the color of the shell.
If you had never seen the shell before eating them, I am guessing nothing would have happened.

I get a headache from eating sandwiches and I have found that the bread is the culprit. Since I found that out I have not eaten bread and have substituted tortillas into my diet. I started having this problem as a teen so you can develop an allergy to eggs at any time. If you are not having a promblem with white eggs, maybe you purchased a bad shipment of brown eggs.

What else was on the sandwich? If the eggs were cooked in butter, you could be lactose intolerant. You might be reacting to the gluten in the wheat bread. I doubt if it's the brown eggs; they're really no different than white ones.

Brown eggs and white eggs only have One difference...color.

So unless you are allerrgic to eggs in general then it is anot an allerrgy.

Were the kept properly? Or are they on thier way out.