Ichthyoses are a group of skin conditions characterised by a generally uniform and persistent pattern of scaling. There are at least 20 varieties of ichthyosis: the most common one is ichthyosis vulgaris, which can occur in conjunction with atopic eczema, and many have keratosis pilaris.
Clinical features of ichthyosis vulgaris may include some of the following:
Small, fine, irregular scales, often curling up at the edges. The scaling, which is semi-adherent, is often much more pronounced on the shins. The scale is usually white-grey, although dark-skinned individuals often have darker scales
While the skin may appear dry or normal at birth, fine scaling is usually apparent by two months of age, although occasionally the diagnosis does not become apparent until the age of five years. The distribution of ichthyosis can be as follows:
It can often be found on the outer parts of the arms and legs and less frequently on the flexural creases or the nappy area (in babies)
The trunk, and in particular the abdomen, is mildly affected. The forehead and cheeks may be involved early on, but scaling usually diminishes in these areas with age
Other types of ichthyosis, besides ichthyosis vulgaris, include X-linked recessive ichthyosis (XLRI), lamellar ichthyosis (LI) and harlequin ichthyosis – these are very rare.
To read more about the dry and itchy skin conditions featured on this page, or for more information about other skin conditions, visit the Primary Care Dermatology Society’s website. This has an A–Z list of a wide range of skin conditions, as well as a list of common conditions