I know I'm allergic to milk (I get itchy skin and respiratory reactions), but I don't know if it's from the lactose or the casein. I know that the product that I react strongest to is ice-cream. I can tolerate some cheeses in small amounts (for whatever reason, swiss is the most reaction-free - but not cheddar). I have used the soy-cheese substitutes before without knowing they contained casein (I didn't know that until I joined this list), and have no conscious memory of reacting to them. Which sounds like I am allergic to lactose and not casein. Is there any way I can know for sure without getting the battery of prick-tests? What foods can I test which contain lactose and not casein? Also, I'm assuming lactose intolerance is different from a lactose allergy. My undertanding is that with an intolerance, the reactions are more related to digestion, while with an allergy, reactions are more related to skin, mucus and respiration. Please correct me if I am wrong in this understanding. Thanks - Liz