Lactose intolerance differs from milk allergy in that it does not require your immune system responding to a trigger molecule. Excess mucus in the throat is also reported by some persons after consuming dairy products, although this is not due to an allergy. Rather, it is due to the fact that cows' milk contains proteins that can cause mucus to rise into the airways. If you are dealing with excess mucus, try reducing your intake of dairy products for a time to see if this helps. Cows' milk contains proteins that can cause inflammation and swelling in the lungs, and these proteins will also affect the lining of the stomach and intestines. Therefore, reducing your intake of cows' milk could help reduce the amount of mucus produced in your body. If you continue to have issues with mucus production, contact your doctor so that you do not develop any allergies or other health problems related to the consumption of dairy products.