What condition is characterized by the buildup of cells?

Keratosis refers to a condition characterized by the buildup of keratin, a protein that forms the outer layer of skin. This buildup can occur due to various factors, including sun exposure or chronic irritation, leading to thicker, rough patches of skin. While it specifically relates to the accumulation of a certain type of cell (keratinocytes), it is a clear example of how skin can react to environmental stressors, resulting in changes to its structure and appearance.

Hyperplasia, on the other hand, describes an increase in the number of cells in a tissue or organ, which can potentially lead to enlarged sizes but does not necessarily imply a buildup of what you would typically see on the skin's surface. Dermatitis involves inflammation of the skin often due to contact with allergens or irritants, which doesn't specifically indicate a buildup of cells but rather an inflammatory response. Acne is primarily caused by excess sebum and clogged pores rather than a generalized buildup of skin cells alone. Thus, keratosis directly aligns with the concept of cell buildup on the skin's surface.