***I copied the following from Living My Dream, I think Sue explains this perfectly in a way I couldn't. I've asked her for permission to post it. Lily's reaction to Dairy seems to be abdominal cramping and a severe persistent diaper rash.***
I have encountered many people who confuse Lactose Intolerance with a Dairy Allergy. So I figured this was the perfect time to post about the difference.
A person with a food intolerance will have an adverse reaction to a food but it does NOT involve the immune system. Someone who is lactose intolerant lacks the enzyme that is needed to break down the sugar in milk known as lactose. The symptoms of lactose intolerance can be gas, bloating and abdominal pain. A person with lactose intolerance CAN drink milk – those I’ve known drink Lactaid which is true milk, but has the lactose taken out.
A food allergy involves the immune system. Basically when someone eats the food, in this case dairy, the body’s immune system mistakes the food as a threat and creates an immune system response – attacking the offending food. A food allergy has the potential to be life-threatening. Signs of a true food allergy can be any or all of the following:
• a tingling sensation in the mouth
• swelling of the tongue and the throat
• difficulty breathing
• abdominal cramps
• drop in blood pressure
• loss of consciousness to death
Symptoms typically appear within minutes to two hours after the person has eaten or has contact with the food to which they are allergic.
It is also important to note that where Lactose intolerance people have trouble breaking down the sugar in milk, a person allergic to dairy reacts to the proteins in milk.
Source: Food Allergy & Anaphylaxis Network