What condition is characterized by blistering or epidermal separation due to lateral pressure on the skin?

The condition characterized by blistering or epidermal separation due to lateral pressure on the skin is known as the Nikolsky sign. This sign indicates a loss of cohesion between the epidermal layers, and when lateral pressure is applied to the skin, the outer layer can easily separate or form blisters. It is often associated with certain skin diseases, including pemphigus vulgaris, a serious autoimmune condition.

The other options represent different skin conditions that do not specifically exhibit this symptom. Dermatitis refers to inflammation of the skin with a variety of forms, including eczema, and is typically associated with itching, redness, and irritation rather than blistering from pressure. Urticaria, or hives, involves raised welts and itchiness due to allergic reactions but does not cause epidermal separation from pressure. Psoriasis is a chronic autoimmune condition characterized by thick, red patches of skin with silvery scales, but it also does not exhibit the Nikolsky sign under lateral pressure. Thus, the Nikolsky sign is the distinct characteristic that correctly aligns with the described condition.