I don't think the suffix "ism" is pejorative in itself. It just implies a system of thought.
Dogma is just an axiom in a religious context. The term axiom is most used in mathematics. In logic an axiom usually is known as premise.
An axiom is a statement taken to be true through pure faith. It's a self evident truth.
At the end of the day axiom, dogma and premise are the same thing.
Scientific method is built upon several axioms.