Final answer:
Psoriasis is a chronic inflammatory skin condition that causes thick, scaly, silvery plaques surrounded by a red area. It commonly affects areas like the elbows, knees, and scalp.
Step-by-step explanation:
Psoriasis is a chronic inflammatory skin condition that produces an excess of thick, scaly, silvery plaques surrounded by a red area. It commonly affects areas such as the elbows, knees, scalp, back, face, palms, and feet. Psoriasis is caused by an interplay between keratinocytes, dendritic cells, and T cells, resulting in the overgrowth of skin cells and inflammation.