Final answer:
Psoriasis is a chronic skin condition marked by red, dry, and scaly lesions, with an underlying cause rooted in the body's immune system response. It is distinct from an infectious disease such as impetigo, which is bacterial in nature.
Step-by-step explanation:
Psoriasis is best described as c. A chronic condition characterized by red, dry, elevated lesions, covered by silvery scales. This skin disease commonly affects areas like the elbows, knees, scalp, back, face, palms, and feet. Unlike other skin conditions such as eczema or impetigo, psoriasis is not an infection but rather an inflammatory condition that results from the interaction of various cells in the skin, including keratinocytes, dendritic cells, T cells, and the cytokines they produce. The thick, red patches of skin with silvery scales are a result of an accelerated process of skin cell turnover, where skin cells rise too quickly to the surface.
It is crucial to correctly diagnose psoriasis, as its treatment and management differ from those required for conditions that are infectious like impetigo, which is often caused by a bacteria called Staphylococcus and is characterized by vesicles, pustules, or bullae with encrusted sores. Psoriasis may also lead to a complication known as psoriatic arthritis, causing inflamed joints.