What type of skin condition is described as the abnormal thick build-up of skin cells?

The condition described as an abnormal thick build-up of skin cells is keratosis. This term is used to refer to any skin condition characterized by an overproduction of keratin, which is a key protein in the skin that helps protect against infection and environmental damage. In keratosis, the accumulation of skin cells can lead to rough, scaly patches that are typically visible on the skin's surface.

Keratosis can manifest in different forms, such as seborrheic keratosis or actinic keratosis, each having specific characteristics and causes, but they share the common feature of an abnormal growth of keratinocytes, the cells that produce keratin.

Other skin conditions listed typically involve inflammation or other issues but do not specifically focus on the abnormal thickening of skin cells. For instance, eczema is primarily an inflammatory condition affecting skin moisture and leading to itchiness, while asteatosis is characterized by dry, scaly skin due to lack of moisture, not an overproduction of cells. Dermatitis refers generally to inflammation of the skin, which can result in various symptoms like redness and irritation, but again, it doesn't emphasize the thickened skin characteristic of keratosis. This reinforces why keratosis is the correct