Information on the following diseases can be found in the Related Disorders section of this report:

• Ichthyosis
• Ichthyosis Congenita
• X-Linked Ichthyosis

Ichthyosis vulgaris is an inherited skin disorder, which begins during the first year of life, although it is usually not present at birth. Symptoms in different patients vary in severity, from mild to severe. The scale is usually fine and white. Only a portion of the body may be involved, but scaling is most common and most severe on the lower legs. Scaling on the torso is less severe and the face is usually unaffected. If the face is affected, the scaling is usually limited to the cheeks and forehead. The sides of the neck and the flexural areas are usually spared. Often, the skin on the palms of the hands and soles of the feet is thickened and may have exaggerated lines.

A skin allergy or eczema (atopic dermatitis) may accompany symptoms in approximately half of patients with this disorder. This disorder tends to improve with age. Symptoms can also improve in warm humid climates or during the summer months.

Ichthyosis vulgaris is an inherited disorder transmitted through an autosomal dominant inheritance. The specific genetic defect that causes ichthyosis vulgaris is not yet identified. Human traits, including classic genetic diseases, are the product of the interaction of two genes for that condition, one received from the father and one from the mother. In dominant disorders, a single copy of the disease gene (received from either the mother or the father) will be expressed, dominating the other normal gene and resulting in the appearance of the disease. In the case of ichthyosis vulgaris, the gene for the disease overrides the gene for normal skin and the individual shows the disease. The risk of transmitting the disorder from an affected parent to offspring is 50 percent for each pregnancy, regardless of the sex of the child.

Ichthyosis vulgaris is a fairly common disorder that affects approximately one in 250 persons in the United States. Males and females are affected in equal numbers.

Symptoms of the following disorders may be similar to those of ichthyosis vulgaris. Comparisons can be useful for a differential diagnosis.

"Ichthyoses" or "disorders of cornification" are general terms describing a group of scaly skin disorders. They are characterized by an abnormal accumulation of large amounts of dead skin cells (squames) in the top layer of the skin. The conversion of an abnormally large number of epidermal cells into squamous cells is thought to be caused by a defect in the metabolism of the skin cells known as "corneocytes" or the fat-rich matrix around these cells. These cells can be thought of as bricks, while the matrix would be the mortar holding these cells together. (See "Ichthyosis" in the Rare Disease Database.)

Ichthyosis congenita (collodion baby; congenital ichthyosiform erythroderma; xeroderma; desquamation of the newborn) is an inherited skin disorder. It is characterized by generalized, abnormally red, dry, and rough skin with large coarse and fine white scales. Itchiness (pruritus) usually also develops. Skin on the palms of the hands and soles of the feet can be abnormally thick. (For more information, choose "Ichthyosis Congenita" as your search term in the Rare Disease Database.)

X-linked ichthyosis is an inherited skin disorder that affects males. It is caused by a deficiency of the enzyme steroid sulfatase. It is characterized by brownish scales on the back of the neck, back and legs.

Ichthyosis vulgaris is treated topically with moisturizers containing urea or glycerol. Lotions containing alpha-hydroxy acids may help. However, some individuals with ichthyosis vulgaris also may experience atopic dermatitis (red, itchy patches of skin) and the alpha-hydroxy acids may irritate their skin.

Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government website.

For information about clinical trials being conducted at the National Institutes of Health (NIH) in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: prpl@cc.nih.gov

For additional information on current research related to ichthyosis vulgaris, contact the Foundation for Ichthyosis & Related Skin Types (FIRST) listed in the Resources section of this report.

Elias, PM, Williams, ML. Enlightened Therapy of the Disorders of Cornification. Clinics in Dermatology. 2003; 21: 269- 273.

DiGiovanna, JJ, Robinson-Bostom, L. Ichthyosis: etiology, diagnosis, and management. Am J Clin Dermatol. 2003; 4: 81-95.

Williams, ML, et al. Genetically Transmitted, Generalized Disorders of Cornification. The Ichthyoses. Dermatol Clin. January 1987; 5(1): 155-78.