Icthyosis

What is ichthyosis?

Ichthyosis is a rare skin disorder which causes dry, scaly skin. It is sometimes known as ‘fish scale disease’. There are in fact many different forms of ichthyosis; some far more severe than others.

The cells in the outer layer of our skin (the epidermis) are constantly dividing and being shed. This process normally takes several weeks, and we are not even aware of it. In ichthyosis, depending on the particular form of the disease, the skin cells either reproduce much faster than they can be shed, with the result that they build up on the skin surface to form scales, or else they reproduce at a normal rate, but instead of shedding from the skin surface they stick to it and produce a build-up of scales.

Who is most likely to suffer from ichthyosis?

Most forms of ichthyosis are inherited, though not all children of sufferers will inherit the ichthyosis gene. In the case of the most common form, ‘ichthyosis vulgaris’, there is a 50% risk of passing the condition on to your children.

Ichthyosis usually first appears in early childhood. It may remain throughout life, although ichthyosis vulgaris usually disappears during adulthood it may recur in old age.

In rare cases, ichthyosis is not an inherited disorder, but is acquired by someone who has no family history of the condition. In such cases it is usually linked with another medical problem, such as kidney disease.

What are the symptoms of ichthyosis?

The symptom common to all forms of ichthyosis is dry, rough, scaly skin. This varies considerably in intensity. In ichthyosis vulgaris, the skin is usually dry and rough with light grey-brown scaling. In more severe forms of ichthyosis, the degree of scaling can be more intense. It may also be painful - the scaly skin can become so tight it restricts body movements, and cracks may develop at skin creases and joints. The scaling of ichthyosis is usually most severe on the legs, but may also involve the arms and hands, and in some cases the trunk and other areas.