context: Many things can leave your skin dry and flaky, from cold air to the chlorine in swimming pools. In a small number of people, a group of diseases called ichthyosis causes skin dryness and scaling. It can't be cured, but treatments can relieve the scaling and make you feel more comfortable in your own skin. Ichthyosis is not one disease, but a family of about 20 skin conditions that lead to dry skin. 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. The condition gets its name from the Greek word for fish, because the skin looks like fish scales. 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 least rare types are: Ichthyosis vulgaris. It affects about 1 out of every 250 people. X-linked recessive ichthyosis. It affects about 1 out of 6,000 people, but only males. It can be inherited or acquired. Inherited ichthyosis: This is caused by mutations, or changes, to genes. Genes are the codes that tell your body to make proteins, which determine how your body looks and functions. Ichthyosis gene mutations affect that proteins that protect your skin and keep it moist. They also affect how quickly skin cells multiply or are shed. Parents pass these genes to their children. Sometimes children whose parents don't have ichthyosis get the disease before birth. The gene change happens inside the egg or sperm -- or when the egg and sperm meet to make a baby. These are called âspontaneous mutations.â Some people have the gene mutation but don't show symptoms. They are called carriers. Acquired ichthyosis: This starts in adulthood. Doctors don't know what causes it. People with the acquired form often have other conditions, such as: Underactive thyroid gland Kidney disease Sarcoidosis, a rare disease that causes patches of inflammation inside the body Cancer such as Hodgkin lymphoma HIV infection Some medicines might also trigger the condition: Cancer drugs such as hydroxyurea ( Droxia, Hydrea), protease inhibitors (a class of drugs used to treat HIV infections), and vemurafenib ( Zelboraf). Nicotinic acid, which is used to treat high cholesterol 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: Testicular cancer Undescended or hidden testicles Low sperm count Other complications include: Vision loss from damage to the cornea (the clear layer in the front of the eye) Brain and nervous system problems 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. She might take a sample of skin to check under a microscope. This is called a biopsy. She might also 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, when 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.