It can. Different people do different things and some are helped by eliminating dairy. Danny is allergic to dairy which we have known since about 2-3 weeks old so we haven't tried it per se but it wouldn't hurt to give it a whirl. Maybe it will help! I know it can make mucous worse even in non asthmatics when they have colds and such so it makes sense to me even from a non-allergy standpoint. I don't think that most or maybe even "many" percentage-wise have this as a trigger/reason but it is certainly possible and worth a try.