But it should be available everywhere. For more info, see my Tests for Lactose Intolerance page. Not at all. They are not even related, although some unfortunate individuals can have both simultaneously. As I've said, LI is simply an insufficient amount of lactase needed to digest the milk sugar, lactose.
Allergies come from proteins.
The body's immune systems treat proteins that leak through the intestines and into the bloodstream the same way they treat truly dangerous invaders, like bacteria. However, there is more than one immune response system in the body. Some of these create what are called hypersensitivities, and these can produce symptoms much like LI, especially in young children. For a much fuller discussion, see my Lactose Intolerance versus Milk Allergy page. Lactase is the last intestinal enzyme to develop and is present in the smallest quantities.