Medically reviewed on March 10, 2018.
Ichthyosis vulgaris (ik-thee-O-sis vul-GAY-ris) is an inherited skin disorder in which dead skin cells accumulate in thick, dry scales on your skin's surface.
The scales of ichthyosis vulgaris, sometimes called fish scale disease or fish skin disease, can be present at birth, but usually first appear during early childhood. Sometimes, mild cases of ichthyosis vulgaris go undiagnosed because they're mistaken for extremely dry skin.
Most cases of ichthyosis vulgaris are mild, but some are severe. Sometimes other skin diseases, such as the allergic skin condition eczema, are associated with ichthyosis vulgaris. No cure has been found for ichthyosis vulgaris, and treatments focus on controlling the condition.
Ichthyosis vulgaris develops when skin cells fail to shed normally and instead accumulate in thick, dry scales. People with darker skin tend to have darker colored scales, as shown here.
Ichthyosis vulgaris slows your skin's natural shedding process. This causes chronic, excessive buildup of the protein in the upper layer of the skin (keratin). Symptoms include:
- Dry, scaly skin
- Tile-like, small scales
- Scales colored white, dirty gray or brown — with darker-colored scales typically on darker skin
- Flaky scalp
- Deep, painful cracks in your skin
The scales usually appear on your elbows and lower legs and may be especially thick and dark over your shins. Most cases of ichthyosis vulgaris are mild, but some can be severe. The severity of symptoms may vary widely among family members who have the condition.
Symptoms usually worsen or are more pronounced in cold, dry environments and tend to improve or even resolve in warm, humid environments.
When to see a doctor
If you suspect you or your child has ichthyosis vulgaris, talk to your family doctor or a dermatologist. He or she can diagnose the condition by examining the characteristic scales.
Also be sure to seek medical advice if the symptoms worsen or don't improve with self-care measures. You may need stronger medication to manage the condition.
Ichthyosis vulgaris is characterized by dry skin with small scales in a color range from white to dirty gray or brown.
Ichthyosis vulgaris is commonly caused by a genetic mutation that's inherited from one or both parents. Children who inherit a defective gene from just one parent have a milder form of the disease. Those who inherit two defective genes have a more severe form of ichthyosis vulgaris. Children with the inherited form of the disorder usually have normal skin at birth, but develop scaling and roughness during the first few years of life.
If genetic abnormalities aren't responsible for ichthyosis, it's referred to as acquired ichthyosis. It's usually associated with other diseases, such as cancer, thyroid disease or HIV/AIDS.
Some people with ichthyosis may experience:
- Overheating. In rare cases, the skin thickness and scales of ichthyosis can interfere with sweating. This can inhibit cooling. In some people, excess sweating (hyperhidrosis) can occur.
- Secondary infection. Skin splitting and cracking may lead to infections.
A doctor can often make a diagnosis by examining the affected skin and the characteristic scales. He or she may perform other tests, such as a skin biopsy. This may be necessary to rule out other causes of dry, scaly skin.
Ichthyosis vulgaris doesn't have a known cure, so the goal of treatment is to manage the condition.
Treatments may include:
- Exfoliating creams and ointments. Prescription creams and ointments containing alpha hydroxy acids, such as lactic acid and glycolic acid, help control scaling and increase skin moisture.
Oral medication. Your doctor may prescribe vitamin A-derived medications called retinoids to reduce the production of skin cells. Side effects from the medication may include eye and lip inflammation, bone spurs and hair loss.
Retinoids may cause birth defects. Women considering retinoid therapy should be sure they are not pregnant before starting the medication — and use effective birth control while taking retinoids.
Lifestyle and home remedies
Self-help measures may help improve the appearance and feel of damaged skin. Consider these suggestions:
- Take long soaking baths to soften the skin. Use mild soap. Rub dampened skin lightly with a rough-textured sponge (loofa) or a pumice stone to help remove the scales.
- After showering or bathing, gently pat or blot the skin dry with a towel so that some moisture remains on the skin.
- Apply moisturizer or lubricating cream while the skin is still moist from bathing. Choose a moisturizer with urea or propylene glycol — chemicals that help keep skin moist. Petroleum jelly is another good choice.
- Apply an over-the-counter product that contains urea, lactic acid or a low concentration of salicylic acid twice daily. Mild acidic compounds help skin shed its dead skin cells. Urea helps bind moisture to skin.
- Use a portable home humidifier or one attached to your furnace to add moisture to the air inside your home.
Preparing for an appointment
If the appointment is for your child, you're likely to start by seeing your child's pediatrician. If the appointment is for you, you're likely to start by seeing your primary care doctor. He or she may refer you or your child to a specialist in skin conditions (dermatologist).
Here's some information to help you prepare for the appointment.
What you can do
Before your appointment make a list of:
- Any symptoms your child or you are experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
- Key personal information, including any major stresses or recent life changes.
- All medications, vitamins or supplements your child or you are taking.
- Questions to ask your doctor.
For ichthyosis vulgaris, some basic questions to ask your doctor include:
- What's the most likely cause of my symptoms?
- Are there other possible causes?
- What kinds of tests will I or my child need?
- Is the condition likely temporary or long lasting?
- What treatments are available and which do you recommend?
- Do you have any brochures or other printed materials I can take with me? What websites do you recommend?
What to expect from your doctor
Questions your doctor is likely to ask include:
- When did the symptoms first appear?
- Are the symptoms constant or do they come and go?
- Does anything help improve the symptoms?
- What, if anything, makes the symptoms worse?
- Does anyone in your family have similar skin changes?
What you can do in the meantime
To help soothe affected skin:
- Wash only with mild soaps that have added oils and fats. Avoid strongly scented and antibacterial soaps, which may be too harsh on dry skin.
- Apply moisturizer or lubricating cream while the skin is still moist from bathing. Choose a moisturizer such as petroleum jelly or one that contains urea or propylene glycol — chemicals that help keep skin moist.