Constant exposure to skin injury results in an increase in the proliferative rate of the keratinocytes. The keratinocytes also mature faster and produce more keratin. In such instances, the thickness of the corneal layer increases. Because of the continuous formation of cells, the number of defective cells increases. It compromises the barrier function of the skin. Defective keratin formation also leads to cellular collapse and blistering. This hyper-proliferative process that leads to increased and defective keratin formation is hyperkeratosis. This hyperkeratosis stimulates the excess production of keratin.