Ichthyosis

Ichthyosis (plural Ichthyoses) is a heterogeneous family of at least 28,^[1 generalized, mostly genetic  skin disorders . All types of ichthyosis have dry, thickened, scaly or flaky skin.^[1 In many types there is  cracked skin,^[2] which is said to resemble the scales on a fish; the word ichthyosis comes from the Ancient Greek ιχθύς (ichthys), meaning "fish."^[3] The severity of symptoms can vary enormously, from the mildest types such as ichthyosis vulgaris which may be mistaken for normal dry skin up to life-threatening conditions such as harlequin type ichthyosisss The most common type of ichthyosis is ichthyosis vulgaris, accounting for more than 95% of cases.^[4]

A physician often can diagnose ichthyosis by looking at the skin. A family history is very useful. In some cases, a skin biopsy is done to help to confirm the diagnosis. In a biopsy, a small piece of skin is removed and examined under a microscope. In some instances, genetic testing may be helpful in making a diagnosis. Diabetes has not been linked to acquired ichthyosis or ichthyosis vulgaris.^[6
Ichthyosis is not more or less common in any ethnic group. As of now, there is no way to prevent ichthyosis since it is often of a genetic nature.

Treatments for ichthyosis often take the form of topical application of creams and emollient oils, in an attempt to hydrate the skin. Retinoids are also used for some conditions. Exposure to sunlight may improve or worsen the condition.
There can be ocular manifestations of ichthyosis, such as corneal and ocular surface diseases. Vascularizing keratitis, which is more commonly found in congenital keratitis-ichythosis-deafness (KID), may worsen with isotretinoin therapy