<prompt> Which among the following is the most common site affected by psoriasis?Flexor surfaceExtensor surfacePalms and solesOral mucosa  <response>: In psoriasis, classically patients develop sharply demarcated red plaques raised plateaulike lesions with silvery white scale distributed about the scalp, trunk, and limbs, with a predilection for extensor surfaces such as the elbows and knees. 