Scaly Skin (Ichthyosis Vulgaris)

Overview

Ichthyosis vulgaris, also known as common ichthyosis or fish scale disease, is a skin condition resulting in scaly skin, especially on the arms and legs. Its name is derived from the Greek word meaning "fish."

Ichthyosis vulgaris can be a trait passed on in families (hereditary), or it may develop later in life as a result of certain exposures (acquired). The hereditary type, also called congenital ichthyosis vulgaris, first appears in early childhood and accounts for more than 95% of cases of ichthyosis vulgaris. The acquired type usually develops in adulthood and results from an internal disease or the use of certain medications.

Who's At Risk

Ichthyosis vulgaris is found in people of all races and of both sexes. Hereditary ichthyosis vulgaris is fairly common. As many as 1 in 250 children may have hereditary ichthyosis vulgaris. On the other hand, acquired ichthyosis vulgaris is rare and is found almost exclusively in adults.

In hereditary ichthyosis, usually at least one of the affected person's parents had the same dry, scaly skin as a child. It is inherited in an autosomal dominant fashion, meaning that each child of an affected parent has a 50-50 chance of having hereditary ichthyosis vulgaris.

Signs and Symptoms

The most common locations for ichthyosis vulgaris include:

• Fronts (extensor surfaces) of the legs
• Backs (extensor surfaces) of the arms
• Scalp
• Back
• Forehead and cheeks, especially in younger children

The scales of ichthyosis vulgaris range in size from 1–10 mm and in color from white to gray to brown, with darker-skinned people often having darker scales. The legs are usually affected more than the arms. The creases on the palms of the hands and the soles of the feet are prominent and often crack during dry or cold weather. However, the scaling tends to improve in more humid or warmer weather.

The following areas tend to NOT be affected:

• Face
• Front of the neck
• Abdomen
• Folds in front of the elbows (flexural surfaces of the arms)
• Folds behind the knees (flexural surfaces of the legs)

Hereditary ichthyosis and acquired ichthyosis look similar, and both are usually itchy. However, the acquired form occurs in people with many internal conditions, including:

• Poor nutrition
• Infections, such as leprosy or HIV/AIDS
• Glandular diseases, such as thyroid or parathyroid problems
• Sarcoidosis
• Cancer, such as lymphoma or multiple myeloma
• Use of certain medications, such as nicotinic acid, cimetidine, and clofazimine

Self-Care Guidelines

Hereditary ichthyosis vulgaris tends to improve after puberty, while acquired ichthyosis vulgaris requires treatment of the medical condition before it will improve.

However, both conditions should improve by restoring moisture (hydration) to the skin. Creams and ointments are better moisturizers than lotions, and they work best when applied just after bathing, while the skin is still moist. The following over-the-counter products may be helpful:

• Preparations containing alpha-hydroxy acids such as glycolic acid or lactic acid
• Creams containing urea
• Over-the-counter cortisone cream (if the areas are itchy)

Any cracks in the skin should be treated immediately with an over-the-counter topical antibiotic ointment (eg, Neosporin®) in order to prevent an infection. 

When to Seek Medical Care

If your child continues to have very dry, scaly skin despite twice daily application of an over-the-counter moisturizer, be sure to tell his/her pediatrician.

Any adult who develops dry, scaly skin that is not improved by twice daily application of an over-the-counter moisturizer should see a physician for evaluation.

Treatments Your Physician May Prescribe

To treat the dry, scaly skin of ichthyosis vulgaris, the physician may recommend a topical cream or lotion containing the following:

• Prescription-strength alpha- or beta-hydroxy acids (glycolic acid, lactic acid, salicylic acid)
• Prescription-strength urea
• A retinoid medication such as tretinoin or tazarotene
• High concentrations of propylene glycol

For more severe, stubborn ichthyosis vulgaris, oral treatments may include:

• Isotretinoin, a very strong medication with many potential side effects, usually used in the treatment of severe, scarring acne

The chance for recovery (prognosis) for a child with hereditary ichthyosis vulgaris is excellent, as most individuals improve after puberty.

If acquired ichthyosis vulgaris is suspected, the doctor will likely attempt to determine the underlying medical condition or the medication that triggered its development. The prognosis for an adult with acquired ichthyosis vulgaris depends upon treating the underlying medical condition or discontinuing the triggering medication.

Trusted Links

MedlinePlus: Skin Conditions

References

Bolognia, Jean L., ed. Dermatology, pp.775-781. New York: Mosby, 2003.

Freedberg, Irwin M., ed. Fitzpatrick's Dermatology in General Medicine. 6^th ed, pp.486, 482, 2353. New York: McGraw-Hill, 2003.