Ichthyosis is the term for severe, persistent problems with dry skin that almost always start in childhood or infancy. Ichthyosis can be genetic (inherited) or can develop later in life. In a large majority of people with the disease, the cause is related to one or more genetic mutations.
Under normal circumstances, the body continuously renews its skin surface, building new skin cells and allowing older cells to be shed from the surface. Ichthyosis disrupts this balance either because too many replacement skin cells are produced or because the skin cells do not separate well from the skin surface when it is their time to drop off. The result is that skin cells accumulate into thick flakes that adhere to the body and can resemble fish scales.
Ichthyosis often causes severe cosmetic concerns for the person with the condition. However, it is not a contagious disease. The condition also can interfere with the skin's critical roles in protecting against infection, preventing dehydration and regulating body temperature.
Most people with ichthyosis have ichthyosis vulgaris, the mildest form of the disease. It occurs in 1 out of every 250 people.
Depending on the type of gene abnormality that causes ichthyosis, the skin can show different patterns of flaking. In most cases of ichthyosis vulgaris, for example, skin will flake over the majority of the body, but not on the inside surfaces of joints, in the groin area or on the face.
Symptoms of all genetic types of ichthyosis are either noticeable at birth or appear during childhood. Symptoms may include:
- Severe dryness of the skin with thickening and flaking, which may be appear only in limited areas or may involve almost the entire skin surface
- Mild itching of the skin
- Body odor, because the spaces under and between skin flakes can harbor collections of bacteria or fungus
- Wax buildup in the ears, causing hearing difficulties
Symptoms are usually worse in winter months and in dry climates, because warmth and humidity improve these symptoms. Many people who have ichthyosis vulgaris also have allergic problems, such as allergic nasal congestion, asthma or eczema.
A doctor usually can diagnose ichthyosis by looking at the skin. A family history is also very useful. In some cases, a skin biopsy will be done to help to confirm the diagnosis. In a biopsy, a small piece of skin is removed and examined under a microscope. In rare instances, genetic testing may be helpful in making a diagnosis.
Most cases of ichthyosis have a genetic basis and will last a lifetime. Sometimes, adult onset ichthyosis occurs in association with a disease, and if the disease can be treated, the ichthyosis may go away. In most people, symptoms can be controlled.
There is no way to prevent ichthyosis. As with other genetic diseases, there is a risk that children of an affected parent will inherit the gene.
Treatment of all types of ichthyosis involves restoring the skin's moisture and facilitating more aggressive shedding of dead skin cells. Regular visits to a dermatologist can help when ichthyosis causes severe symptoms.
To get the best results, use moisture-retaining creams or ointments after a bath or shower, so that moisture is maintained within the skin surface. Petrolatum, lanolin or urea-containing preparations are very helpful in maintaining skin moisture.
Medicines that promote shedding of skin flakes include lotions or creams that contain lactic acid or other "alpha-hydroxy acids."
If the ichthyosis leads to scratching that causes skin infections, or if body odor is a major problem, antibiotics may be needed from time to time.
Because ichthyosis can make the skin a less effective barrier to infection, it is important to contact a physician if you develop a fever or redness of the skin.
With continued effective treatment and good advice about skin care, ichthyosis is usually very manageable. Some forms of ichthyosis improve after childhood. Rare forms of ichthyosis can be life threatening, even in infancy, if skin problems are severe.
American Academy of Dermatology
P.O. Box 4014
Schaumburg, IL 60168-4014