What term describes the abnormal thickening of the stratum corneum?

The term that describes the abnormal thickening of the stratum corneum is hyperkeratosis. This condition occurs when there is an overproduction of keratin, a protein that makes up the outer layer of the skin. The stratum corneum is the outermost layer of the epidermis, and its thickening can be a response to various stimuli, such as chronic friction, irritation, or certain skin conditions.

Hyperkeratosis can manifest in a variety of skin disorders, and it often presents as rough, thickened patches of skin. Understanding this definition helps to distinguish it from other dermatological terms. For example, dermatitis refers to inflammation of the skin and is not solely focused on the stratum corneum. Ichthyosis is a condition characterized by dry, scaling skin due to a defect in skin cell maturation or turnover, but it would not specifically denote thickening of the stratum corneum alone. Psoriasis is an autoimmune condition that can involve hyperkeratosis but is characterized by systemic inflammation and other features beyond just thickening of this skin layer.

Thus, hyperkeratosis stands out as the precise term for this specific alteration in the skin's structure.