Ichthyosis is a family of rare genetic skin disorders characterized by dry, thickened, scaly skin. There are more than 20 types of ichthyosis range in severity of symptoms, outward appearance, underlying genetic cause, and mode of inheritance. Ichthyosis literally “fish”, since dry, scaly skin is the defining feature of all forms of ichthyosis.
The severity of symptoms can vary enormously, from the mildest, most common. Types such as ichthyosis vulgaris, which may be mistaken for normal dry skin, up to life-threatening conditions such as harlequin-type ichthyosis. Ichthyosis vulgaris accounts for more than 93% of cases.