Medically Reviewed by Stephanie S. Gardner, MD on April 26, 2022
4 min read

Ichthyosis is a group of about 20 skin conditions that cause skin dryness and scaling. The condition gets its name from the Greek word for fish, because the skin looks like fish scales. You might also hear it called fish scale or fish skin disease.

People with this condition lose the protective barrier that keeps moisture in their skin. They also make new skin cells too quickly or shed old cells too slowly. This leads to a buildup of thick, scaly skin. Most cases of ichthyosis are mild.

Ichthyosis can't be cured, but treatments can relieve the scaling and make you feel more comfortable.

Some types only cause dry and scaly skin. Others cause problems inside the body, too.

Most forms of the disease are very rare. The two most common types are:

  • Ichthyosis vulgaris. It affects about 1 out of every 250 people. Gray, brown, or white scales can show up in early childhood.
  • X-linked recessive ichthyosis. It affects about 1 out of 6,000 people, but only males. It can raise your risk for testicular cancer. Women can be carriers and may have labor problems.

Inherited ichthyosis is a genetic condition. That means it’s passed down to you from your parents. Genes are the codes that tell your body to make proteins, which determine how your body looks and functions. When there are changes or mutations to a gene, it can cause disease. Ichthyosis gene mutations affect the proteins that protect your skin and keep it moist. They also affect how quickly your body sheds or grows new skin cells.

Ichthyosis usually shows up in early childhood. If both of your parents have the gene, you’re likely to have a more serious condition than if only one of them has the gene.

Acquired ichthyosis shows up in adulthood. Doctors don’t know what causes it, but people with it often have other conditions, including:

Some medicines might also trigger the condition:

In the inherited forms, symptoms appear at birth or in the first few months of life.

Dry, scaly skin is the main symptom. The scales form on only some parts of the body, such as the:

  • Trunk
  • Stomach
  • Buttocks
  • Legs
  • Face and scalp

The scales can be white, gray, or dark brown. They might have thick or thin cracks running through them.

Dryness and scaling get worse in cold, dry weather. They usually improve in warmer weather.

Other signs of ichthyosis are:

  • Skin redness
  • Blisters
  • Peeling
  • Itchiness
  • Pain
  • Lines on the palms of the hands and soles of the feet
  • Tight skin that makes it hard to move

Many people with ichthyosis also have eczema, a red, itchy rash.

Skin is your body's barrier. It holds moisture inside and keeps out bacteria and other invaders that might make you sick. When ichthyosis makes pieces of your skin scale off, you lose some of this protective layer.

Scaling can lead to complications such as:

  • Infections
  • Dehydration
  • Blocked sweat glands, which can lead to overheating
  • Slow hair growth from scales on the scalp
  • Burning more calories, because the skin has to work harder to turn over cells

Ichthyosis can cause emotional issues, too. The scales can affect the way you look. People with this condition sometimes feel depressed and have low self-esteem.

Men with ichthyosis are also at increased risk for:

Other complications include:

Sometimes it’s so mild that it looks like regular dry skin. If the dryness and scaling bother you, see a dermatologist -- a doctor who treats skin problems -- for treatment. They may:

  • Take a sample of skin to check under a microscope. This is called a biopsy.
  • Test your saliva for gene changes that cause certain types of ichthyosis.

It can't be cured, but treatments can help you manage dry and scaly skin.

Rub cream, lotion, or ointment onto your skin every day to add moisture. Look for rich creams that have any of these ingredients: lanolin, alpha hydroxy acids, urea, or propylene glycol. Products with ceramides or cholesterol also keep skin moist.

Apply the lotion right after you step out of the shower or bath, while your skin is still damp. This will help hold in moisture. Other things you can try:

  • Take baths in salt water.
  • Rub your skin with a pumice stone.
  • Remove dead skin with a product that contains salicylic acid, glycolic acid, or lactic acid.

If the dryness and scaling are severe, your doctor might prescribe an oral retinoid medicine such as acitretin (Soriatane) or isotretinoin (Absorica, Claravis, Sotret, and others). Retinoids can cause side effects such as weakened bones, dry mouth, and upset stomach.

Ichthyosis isn't life-threatening, but it can be life-changing.

Your dermatologist can recommend treatments to help your skin look and feel better. If you feel depressed or have low self-esteem, talk to a therapist or other mental health experts.

Show Sources

Photo Credit: Science Photo Library / Science Source

American Academy of Dermatology: "Dry Skin: Who Gets and Causes."

British Skin Foundation: "Ichthyosis."

DermNet New Zealand: "Ichthyosis," "Ichthyosis Vulgaris," "Recessive X-linked ichthyosis."

First Foundation for Ichthyosis & Related Skin Types: "Living with Ichthyosis," "X-Linked Ichthyosis Fact Sheet."

Mayo Clinic: “Ichthyosis Vulgaris”

Medscape: "Ichthyosis."

National Health Service: "Ichthyosis."

National Institute of Arthritis and Musculoskeletal and Skin Diseases: "Ichthyosis."

National Organization for Rare Disorders: "Ichthyosis."

National Institutes of Health-U.S. National Library of Medicine: “What is a gene?”

National Institutes of Health, AIDSinfo: “Protease Inhibitor.”

National Organization for Rare Disorders – Photo Caption

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