Buffalo milk is commonly drunk in many countries and it is becoming increasingly popular in Western countries along with it's by-products, such as buffalo mozzarella.
The allergenic proteins in buffalo milk are generally split into albumins (commonly called whey) and casein. In human milk the split is usually 60% whey to 40% casein. In buffalo milk the split is 20% whey to 80% casein. This is a very similar composition to cow's milk. This massive difference in composition is thought to be the cause of what causes IgE allergic reaction to mammalian milk, with most people being allergic to casein proteins in the milk.
Buffalo milk allergy is not currently associated with any syndromes.
Cow, goat and sheep milk could all be cross reactive with buffalo milk due to similar composition.