Psoriasis is characterized by which feature?

Psoriasis is primarily characterized by the presence of red patches covered with silvery-white scales. This distinctive appearance is due to the rapid turnover of skin cells, which leads to the buildup of skin on the surface. The patches can vary in size and may be itchy, but the hallmark features that set psoriasis apart are the red color and the scaling. This condition is an autoimmune disorder that can result in discomfort and can also affect other areas of health.

The other options describe features associated with different skin conditions. Blisters filled with clear fluid might indicate conditions such as eczema or a contact dermatitis, while itchy red bumps are often seen in allergic reactions or insect bites. Dark brown circles could refer to hyperpigmentation, which is unrelated to psoriasis. Thus, when identifying psoriasis, the correct choice is indeed those red patches with silver-white scales, which clearly define its clinical presentation.