What Is It?
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 one 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.