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Ichthyosis vulgaris: Overview

Ichthyosis is a group of skin diseases that causes extremely dry, thick, and scaly skin. The skin often looks like it has fish scales.

There are more than 20 different types of ichthyosis. The most common type is ichthyosis vulgaris. About 95% of people who develop ichthyosis get this type.

Ichthyosis vulgaris

The skin cells build up, causing thick flakes that can resemble fish scales.

Ichthyosis vulgaris on arm

The other types are rare and include harlequin ichthyosis, lamellar type, and x-linked ichthyosis.

Of all the types, ichthyosis vulgaris is the mildest. It often begins in childhood.

Children usually develop it when they inherit a gene(s) for the disease from one or both parents. A parent doesn’t have to have the disease to pass on these genes. Because it is passed through the genes, this type is called inherited ichthyosis vulgaris.

Adults can also develop ichthyosis vulgaris, but this is rare. Adults get acquired ichthyosis vulgaris. It’s called “acquired” because you get it when a disease or medicine that you’re taking causes ichthyosis to develop. Diseases that can trigger this type of ichthyosis include kidney failure, some cancers, and human immunodeficiency virus (HIV).

Whether ichthyosis vulgaris begins in a child or adult, it can be so mild that is mistaken for extremely dry skin. Many people never realize they have ichthyosis because applying moisturizer keeps their skin free of scale.

Is ichthyosis vulgaris contagious?

Ichthyosis isn’t contagious, so you cannot catch it from someone.

When to see a dermatologist

If applying moisturizer twice a day fails to get rid of the scaly skin, you should see a board-certified dermatologist to find out if you have ichthyosis or another skin condition.

Image used with permission of Journal of the American Academy of Dermatology: J Am Acad Dermatol. 2006; 55:647-56.

Fleckman P and DiGiovanna JJ. “The ichthyoses.” In: Wolff K, Goldsmith LA, et al. Fitzpatrick’s Dermatology in General Medicine (seventh edition). McGraw Hill Medical, New York, 2008:401-424.

James WD, Berger TG, et al. “Genodermatoses and congenital anomalies.” In: James WD, Berger TG, et al. Andrews' Diseases of the Skin, Clinical Dermatology (tenth edition), Elsevier, Canada, 2006:560-1.

Richard G and Ringpfeil F. “Ichthyoses, erythrokeratodermas, and related disorders.” In: Bolognia JL, et al. Dermatology. (second edition). Mosby Elsevier, Spain, 2008:743-9.

Schwartz RA. “Hereditary and acquired ichthyosis vulgaris.” In: Elston DM, (chief editor) Medscape. Last updated June 22, 2016.