My puppy has patchy hair loss on his muzzle and over his eye. Any Ideas what this could be?

My 5 month old male pit bull puppy has some hair loss over his left eye and on the left side of his nose on his muzzle. There is no scaly or crusty skin, nothing that looks menacing aside from the hair loss itself. Anyone have any ideas as to why this is happening and what I can do about it? Thanks in advance!