<unk>  is thickening of the stratum corneum (the outermost layer of the epidermis, or skin), often associated with the presence of an abnormal quantity of keratin, and also usually accompanied by an increase in the granular layer. As the corneum layer normally varies greatly in thickness in different sites, some experience is needed to assess minor degrees of<unk> . It can be caused by vitamin A deficiency or chronic exposure to arsenic.<unk>  can also be caused by B-Raf inhibitor drugs such as Vemurafenib and Dabrafenib. It can be treated with urea-containing creams, which dissolve the intercellular matrix of the cells of the stratum corneum, promoting desquamation of scaly skin, eventually resulting in softening of hyperkeratotic areas.
Hyperkeratosis
Porokeratosis
Parakeratosis
Hyperkeratinization
Hyperpigmentation
Glycogenic acanthosis
Granulomatous slack skin
Epidermolytic hyperkeratosis