Many people are hypersensitive to dairy products and other foods and don't even know it because they never make the connection between low-grade symptoms and something they've eaten. If you notice some stuffiness/congestion, chest tightness, aches and pains, indigestion, skin rash, diarrhea, rapid pulse rate, sleeplessness or some other symptom that is becoming chronic, you may want to try this simple test at home:
-Eliminate the food or ingredient you suspect of causing the symptoms from your diet for 7 days. You can omit several ingredients at the same time (dairy, wheat, eggs or whatever you suspect is causing it), and note how you feel in a diary. If you are not sure of what u should omit, think of what you eat the most of and cut them out. we tend to be allergic to foods that we consume too much of interestingly enough.
-Its common to feel worse on the 3rd and 4th day. Note this if you do.
-Your allergy symptoms should start to feel much better on days 5 through to 7 (if the allergen is amongst the foods that you cut out). Again note this down.
-On Day 8, re-introduce the food that you have ommitted. Do not eat it with any other food and wait for 3 hours before eating anything else. If you've omitted more then one food, introduce each one exclusively on alternate days. For example if you've stopped wheat and dairy, introduce wheat on day 8, then on day 9 stop wheat and have dairy.
If you are allergic to the food you reintroduced, the reaction will be very obvious and you should limit your intake of that food to once a week or stop it completely depending on the severity of the reaction.