Ichthyosis is a genetic skin disorder. It is characterized by dry skin that builds up and flakes off. The skin can sometimes appear to be scales, which is where the name originates; ichthys means "fish" in ancient Greek. There are several types of genetic ichthyosis and each presents in a slightly different fashion. These types are ichthyosis vulgaris, lamellar ichthyosis, epidermolytic hyperkeratosis, X-linked ichthyosis, and congenital ichthyosiform erythroderma.
Ichthyosis vulgaris accounts for 95% of cases, making it the most common form. It is usually found on the trunk and legs and makes its appearance at puberty. Epidermolytic hyperkeratosisis is seen as red, moist skin at birth. Lemellar Ichthyosis is an extremely rare version where babies are born with a mucus membrane over their skin and the entire body sheds. X-linked ichthyosis is found on the trunk and extremities and is present at birth. Congenital ichthyosiform erythroderma is the mildest of the forms of the disease and is present at birth with mild scaling into adulthood.
There is one form of ichthyosis that does not appear to be genetic. It is called ichthyosis acquisita, or acquired ichthyosis. This disorder is usually a sign of another disease such as Hodgkin's Disease, leprosy, typhoid fever or other malignancy. In rare instances, it has been linked with certain medications.
Ichthyosis is usually diagnosed by its appearance. Doctors can generally recognize the symptoms of it without a great deal of testing. In some cases, a sample of the skin may be taken and tested to confirm their suspicions. Usually, a look at family history in conjunction with the appearance of scales is a good indicator of the disease.
The disorder is usually treated in a non-invasive manner with salves and creams. There is no cure for the disease, so the goal is to reduce the appearance of the scales and relieve any discomfort it may cause. Creams usually contain alpha hydroxy acids that moisturize the skin. Occasionally, retinoids may be prescribed. These creams are derived from Vitamin A and can slow the regeneration of skin. Since the disorder is a buildup of skin, the slowing of regeneration can help to calm the process in extreme cases.