There are two ways of getting this disease. The disease can be genetically inherited from a parent or caused by a genetic mutation resulting in the inactivation of certain enzymes. Normal skin regenerates about every fourteen days. The cells originate from the basal epidermis and migrate to the surface. As it migrates, the cells differentiate and at the surface the old cells shed.
Normal skin sheds whole individual skin cells or small pieces of microscopic whole skin cell.
This process is invisible to the naked eye. For patients with ichthyosis the shedding is visible. The skin cells are shed in large enough pieces to be seen with the naked eye. Large pieces of skin cells are formed because the rate of cell production is faster than the rate of shedding. In the intercellular space cholesterol and cholesterol sulfate can be found.