Breisheet is the story of G-d's creation, whereas Tazria details the creation of man. Just as man was banished from Gan Eden, the metzora is banished from the camp of Israel.
Speech is a most powerful tool. The way we talk to G-d, to our children, our neighbours, our colleagues, our friends and even our enemies will determine our fate. Will we be banished from the presence of G-d, or will we merit living up to our tzelem Elokim?