Which skin condition is characterized by silvery scales on extensor surfaces?

Psoriasis is characterized by the presence of silvery scales, particularly on extensor surfaces such as the elbows and knees. This chronic autoimmune condition results from rapid skin cell proliferation, leading to thickened, scaly areas that are often red and inflamed underneath the scales. The specific morphology of the lesions, along with their typical location, aids in differentiating psoriasis from other skin conditions.

In contrast, eczema generally presents with dry, itchy patches of skin that can appear anywhere on the body, primarily on flexor surfaces, and is often associated with a personal or family history of atopy. Dermatophyte infections or fungal infections typically manifest as ring-shaped lesions with a raised border and may or may not involve scaling. Contact dermatitis occurs due to an allergic or irritant response to a substance, presenting with redness, swelling, and vesicles rather than distinct silvery scales. Thus, the unique appearance and specific location of the lesions in psoriasis make it the correct response.