What condition is characterized by plaques with silvery scales, commonly found on elbows and knees?

The condition characterized by plaques with silvery scales, particularly found on the elbows and knees, is psoriasis. This chronic autoimmune skin disorder leads to the rapid proliferation of skin cells, resulting in the buildup of thick, scaly plaques that often have a distinctive silver appearance. Psoriasis is commonly mistaken for other skin conditions, but its defining features include the specific location of lesions (such as extensor surfaces like the elbows and knees) and the silvery-white scaling that separates it from other dermatologic diseases.

In contrast, eczema (also known as atopic dermatitis) usually presents with red, itchy, and inflamed skin rather than the silvery scales seen in psoriasis. Seborrheic dermatitis tends to cause flaky, greasy patches and crusting in areas rich in sebaceous glands, such as the scalp and face, not specifically on the elbows and knees. Contact dermatitis results from a direct allergic reaction or irritation from external substances, leading to redness and vesicles rather than silvery scaling. These distinctions clarify why the condition described in the question is indeed psoriasis.