I am on advair and it says not to have milk proteins. what does that mean? what are milk proteins?

Milk allergy warning: "advair diskus (salmeterol and fluticasone) contains lactose. Do not use Advair Diskus (salmeterol and fluticasone) if you have severe allergy to milk proteins." lactose is a milk sugar. People with milk allergies typically react to milk proteins. The lactose in advair may be contaminated with trace amount of milk proteins. Warning only applies to people with severe milk allergies who may react to trace amount of milk protein in advair diskus (salmeterol and fluticasone).