Concerned about my birds beak

I have a two year old female budgie bird.She may have mites or a fungus and it's affecting her beak.Her beak is growing improperly and is crusty.There's black around her beak and inside the upper part of her beak.She itches her head and neck,too.Is there something I can buy to treat this problem? Should I take her to see a avian vet? Please respond.Thanks.