Since my mom has crohn's disease and i have psoriasis am i likely to develop crohn's disease too? does this increase chance of arthritis?

A chance: Crohn's has a genetic component. Offspring have about a 5% chance of getting crohn's if a parent has it. There is also an overlap between crohn's, psoriasis and arthritis, i.e. An increased associated risk. The good news is that if crohn's is treated early, there is probably a better outcome. So by being aware of your risks, you are doing your best and ahead of the game.