Dry, Cracked Skin (Xerosis): Causes, Symptoms and How to Keep Skin Moisturized

3 days ago

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Dry skin (xerosis, or xeroderma) is a condition in which the outermost layer of the skin loses oil and water faster than it can replace them. The skin becomes rough, tight, flaky and itchy, especially on the shins, arms, hands and heels. Most dry skin improves within 1–2 weeks when you choose the right type of moisturizer and apply it at the right time. But dry skin that itches so much you cannot sleep, cracks into red lines, or has been dry and scaly since childhood often has an underlying condition and needs additional treatment.

From October to January the air in Thailand becomes drier, relative humidity in some areas falls below 40%, and many people take very hot showers, so dry skin becomes noticeably more common. This article explains how the different types of dry skin differ, which cream ingredients actually work, what concentration to use, how many times a day to apply them, and which signs mean you should see a dermatologist.

What is dry skin (xerosis), and how does it differ from dehydrated skin?

The outermost layer of the skin (stratum corneum) works like a brick wall. The skin cells are the bricks, and the lipids between the cells, namely ceramides, cholesterol and fatty acids, are the mortar that holds them together. Inside the cells there are also natural water-binding substances (natural moisturizing factor) made from a protein called filaggrin. When the mortar or the water-binding substances decrease, water evaporates from the skin more easily. Skin that normally holds about 20–30% water drops below 10% and begins to feel dry, flake and crack.

Dry skin: the skin lacks oils and water-binding substances. It affects the whole body or recurs regularly, and it usually gets worse with age. The oils need to be replaced with a cream that contains ingredients that coat the skin.
Dehydrated skin: a temporary condition in which the skin lacks water. Even people with oily skin can have it, for example after sun exposure, a full day in an air-conditioned room, or using acne medication. It resolves faster once you stop the trigger.

How to tell if you have dry skin, and which levels you can manage yourself

Dermatologists usually divide the severity of dry skin into 4 levels, which helps decide whether you can care for it yourself or need medication.

Level 1, mild dryness: the skin feels tight after a shower, and a fingernail scratch leaves a white line. There are no obvious flakes yet.
Level 2, dry and flaking: there are fine, white, powdery flakes, especially on the shins and outer arms, and the skin starts to itch.
Level 3, dry and scaly: the flakes form small plates arranged like fish scales. The skin is rough and clearly itchy.
Level 4, dry and cracked: the skin splits into shallow grooves like dry earth or cracked tiles. The grooves are red and sting, and some spots ooze blood. At this level it has usually become an inflamed rash.

Levels 1–2 can be managed at home with a moisturizer. For levels 3–4, you should use a cream with an ingredient that helps shed scales, or an anti-inflammatory medicine, and if there is no improvement after 2 weeks of care, you should have a doctor examine it.

What causes dry skin?

Dry skin results from a combination of external and internal factors. Most people have more than one.

Dry, cold air: air humidity below 40% makes water evaporate from the skin faster. Air-conditioned rooms also draw moisture out of the air.
Hot, long and frequent showers: hot water dissolves the oils on the skin. Showering for more than 10 minutes or more than twice a day clearly increases dryness.
Alkaline soaps and cleansers: ordinary bar soap has a pH of about 9–10, while normal skin has a pH of about 4.5–5.5.
Age: after age 60 the skin produces far fewer oils and water-binding substances. More than half of older adults have dry skin.
Genetics and skin diseases: for example atopic dermatitis and inherited scaly dry skin, in which the gene that makes filaggrin is faulty.
Medical conditions: underactive thyroid, chronic kidney failure, diabetes, and certain nutritional deficiencies.
Medicines: for example isotretinoin, diuretics, cholesterol-lowering drugs and some cancer treatments.

Why does dry skin itch at night, and why is it drier in the cool season?

Many people notice that during the day their skin is only tight, but at bedtime it itches so much they have to scratch. This comes from several mechanisms that happen together at night.

The skin loses the most water from evening into the night. Measurements of transepidermal water loss show that it rises during this period.
Skin temperature rises when you are under a blanket and lying still. Heat stimulates the nerve endings that sense itch.
The hormone cortisol, which helps reduce inflammation, is at its lowest in the middle of the night.
There is nothing to distract you, so the brain notices the itch more clearly.

Scratching damages the skin barrier further, which makes the itch worse and leads to more scratching. This loop is called the itch–scratch cycle. Applying a moisturizer before bed and keeping the air conditioner from getting too cold and dry helps a great deal. If you itch at night but can barely see any dry skin, read more in Itching all over at night: what is just dry skin and what is a sign of disease

Age-related dry skin in older adults, and asteatotic eczema

Appearance: dry skin all over, most noticeable on the shins, arms and back. If the dryness continues, the skin cracks into red grooves like cracked tiles or dry ground, called asteatotic eczema (eczema craquelé). It usually appears on both shins.

Cause: the skin produces fewer oils with age, combined with hot showers, harsh soaps and cold weather. It is especially common in older adults who take diuretics or spend all day in air-conditioned rooms.

Severity/urgency: ordinary dry skin is not urgent, but once the skin cracks into red lines it is an inflamed rash, a moisturizer alone is usually not enough, and the cracks give bacteria a way in.

When to see a doctor: when the skin cracks into red lines or oozes fluid, when the itch keeps you from sleeping, or when a rash on one leg is swollen and warm, which has to be told apart from a rash caused by varicose veins and from infection. See also Itchy rash on the legs: telling stasis dermatitis from asteatotic eczema and Skin care in older adults

Dry skin from atopic dermatitis

Appearance: dry skin all over together with a red, itchy rash that comes and goes. In children it usually appears on the cheeks and the outer sides of the arms and legs. In older children and adults it usually appears in the creases of the elbows and knees, on the neck and around the eyes. There is often a family history of allergies, asthma or allergic rhinitis.

Cause: a skin barrier that is faulty from birth, together with an overreactive immune system. The skin is dry even when you have done nothing wrong, and it is easily irritated by sweat, wool, fragrance and soap.

Severity/urgency: it is a chronic disease, and dry skin is its foundation. If dry skin is well managed, flare-ups become clearly less frequent. Regular moisturizing in at-risk infants also helps lower the chance of developing the rash.

When to see a doctor: when there is a red, itchy rash that keeps returning in the skin creases, a rash that weeps or has yellow crusts, or a child who cannot sleep because of itching. Read more about atopic dermatitis

Scaly dry skin since childhood (ichthyosis vulgaris)

Appearance: fine white or grey scales arranged like fish scales, most noticeable on the shins and outer arms, while the skin creases are usually spared. The palms have more and deeper lines than usual. It usually starts in the first year of life and improves in summer.

Cause: an inherited fault in the gene that makes the protein filaggrin. It affects about 1 in 250 people and often occurs together with atopic dermatitis.

Severity/urgency: it is not dangerous, but it lasts for life. An ordinary moisturizer helps little, and you usually need a cream with a scale-shedding ingredient, such as urea 10–20% or lactic acid 12%, applied every day.

When to see a doctor: when the skin has been scaly since childhood or is scaly all over, to tell it apart from other types of scaly skin, and when the scales first appear in adulthood, because scaly skin that starts in adults can be linked to medical conditions such as underactive thyroid, kidney failure or lymphoma.

Dry skin from medical conditions: underactive thyroid, kidney failure, diabetes

Appearance: dry skin all over that has only just started and does not improve even with regular moisturizing. There are often other symptoms as well.

Cause: dry skin is a symptom of many diseases. The common ones are:

Underactive thyroid (hypothyroidism): rough, cold, pale-yellow dry skin together with feeling cold, weight gain, fatigue, and thinning hair and eyebrows.
Chronic kidney failure: dry skin affects more than half of dialysis patients, who often have severe itching all over, especially at night.
Diabetes: dry skin especially on the legs and feet, heels that crack easily, and slow-healing wounds. See also Skin conditions caused by diabetes

Severity/urgency: dry skin is a warning sign of a disease that has to be treated at its source. Cream alone helps only partly.

When to see a doctor: when dry, itchy skin all over has only just started in adulthood together with weight changes, fatigue, swelling, abnormal urination or night sweats. The doctor may order blood tests for thyroid, kidney and liver function, blood sugar, blood count and iron.

Dry skin from medicines

Appearance: dry, flaking or itchy skin that starts a few weeks after beginning a new medicine.

Cause: medicines that often cause dry skin include:

Isotretinoin, an acne medicine: almost everyone gets dry, cracked lips, and many get dry skin on the body.
Topical retinoids such as tretinoin and adapalene make facial skin dry and flaky during the first 2–4 weeks.
Diuretics such as hydrochlorothiazide and furosemide.
Cholesterol-lowering statins.
Some cancer medicines, especially EGFR inhibitors.

Severity/urgency: mostly not dangerous and can be managed with a moisturizer. Do not stop medicine for a chronic condition on your own.

When to see a doctor: when the dryness is so severe that the skin cracks, or you develop a red rash, blisters or sheet-like peeling after starting a medicine. This may be a drug allergy, so see a doctor immediately and tell the doctor who prescribed the medicine so they can consider adjusting it.

Dry hands from frequent hand washing

Appearance: the backs of the hands and the knuckles are dry, rough and cracked into grooves, and sting when they touch water or alcohol. It is common in people who do housework, nurses, cooks, hairdressers and people who look after young children.

Cause: water, soap and dish detergent strip oil from the skin of the hands dozens of times a day. If left alone it becomes irritant hand dermatitis.

Severity/urgency: it can become chronic unless you reduce contact with water. One thing many people do not know is that an alcohol gel containing moisturizing ingredients irritates the skin less than frequent washing with soap.

When to see a doctor: when the hands crack into open sores, have clear blisters, itch a lot, or do not improve within 2 weeks, because it may be contact dermatitis or another condition. Read more in Peeling hands: what is just dryness and what is a disease and Contact dermatitis

Dry skin on the legs, shins and cracked heels

Appearance: the shins are the first place to dry out because they have the fewest oil glands in the body. The flakes are small plates like scales. The heels are thick, hard and cracked into deep grooves, and some grooves are deep enough to bleed and hurt when you walk.

Cause: the skin of the shins naturally has little oil, while the heels bear pressure all day, so the skin thickens. Wearing open-back sandals or walking barefoot makes heels crack even more easily.

Severity/urgency: mostly not dangerous, but in people with diabetes or narrowed blood vessels in the limbs, cracks in the heels are an entry point for germs and can become chronic wounds.

When to see a doctor: when cracked heels bleed, are painful, swollen, red or have pus, or when you have diabetes, and also when the feet peel with itching between the toes, which may be a fungal infection. See also Cracked heels and Peeling feet: telling fungus from dry skin

Dry, flaky facial skin

Appearance: the face feels tight and has thin flakes around the nose, mouth and cheeks, especially after washing.

Cause: washing the face too often or using a very foamy cleanser, using acne medicine or retinoids, overusing scrubs or exfoliating acids, and spending all day in air conditioning.

Severity/urgency: not dangerous, but many kinds of facial flaking are not dry skin, for example oily yellow flakes beside the nose, on the eyebrows and in the hairline, which are seborrheic dermatitis and need a different type of medicine from dry skin.

When to see a doctor: when the face flakes together with red patches, greasy scales, or stinging and burning every time you apply a cream.

Which moisturizer is best: ointment, cream or lotion?

The texture of the product matters as much as the ingredients, because the more oil it contains, the better it coats the skin and prevents water from evaporating.

Ointment: almost entirely oil, such as petroleum jelly (petrolatum). It coats the skin more tightly than other textures and reduces water evaporation by more than 98%. It contains few preservatives, so it stings less. It suits cracked dry skin, heels and bedtime use. The downside is that it feels greasy.
Cream: oil and water in roughly equal parts. It absorbs more easily and suits level 2–3 dry skin and daytime use.
Lotion: mostly water. It is light and easy to apply on hairy skin, but gives the shortest-lasting moisture. It suits mild dryness or hot, humid weather.
Gel: almost no oil, so it is not suitable for dry skin.

A simple rule: the drier the skin, the heavier the texture you should choose, and choose a fragrance-free formula, because fragrance is a leading cause of contact dermatitis from cosmetics.

Effective ingredients for dry skin creams, and the concentrations to use

Moisturizers work in 3 ways: drawing water into the skin (humectant), coating the skin to stop water evaporating (occlusive), and replacing the lipids between cells (emollient). A good cream should have at least 2 of these.

Urea: at a concentration of 5–10% it draws water into the skin and suits the whole body 1–2 times a day. At 20–40% it helps shed thickened skin and dissolve scales, and is used only on the heels, elbows and thick scaly skin, once a day at bedtime. You usually see results in 1–2 weeks. Be careful, because it stings on cracked skin, and high concentrations should not be used in young children.
Lactic acid or ammonium lactate 12%: helps shed scales and adds moisture. It suits scaly shins and inherited scaly skin, applied twice a day. It may sting at first, should not be applied on cracked skin or used in infants, and you should use sunscreen on areas exposed to the sun.
Glycerin: draws water into the skin, is gentle, and can be used at any age. Formulas that work well usually have a concentration of about 5–20%.
Ceramide: replaces the lipids the skin lacks. It suits atopic dermatitis and works better when combined with cholesterol and fatty acids.
Petrolatum, dimethicone and mineral oil: they coat the skin, are inexpensive and cause very little irritation.
Colloidal oatmeal: helps reduce mild itching and suits sensitive skin.

Signs that a cream is working: tightness and itching ease within 3–7 days, and flakes clear within 1–2 weeks. If you have applied it correctly for a full 2 weeks and it still itches or there is a red rash, it may not be ordinary dry skin, or it may have become an inflamed rash that needs medication.

Things to avoid on dry skin include fragrance, high amounts of alcohol, essential oils and bead scrubs.

How to apply moisturizer so it works: the 3-minute rule

Apply within 3 minutes after a shower. Pat the body until just damp, do not dry it completely, and apply right away to trap the water the skin has just absorbed.
Apply at least twice a day, after the morning shower and before bed, and apply again to the hands every time after washing them.
Apply enough. Adults covering the whole body usually use about 15–30 grams each time. For atopic dermatitis, treatment guidelines suggest about 250–500 grams per week. Many people do not improve simply because they apply too little.
Smooth it on in the direction of hair growth, without rubbing back and forth hard, to reduce clogged hair follicles.
Keep applying even after the skin improves. Dry skin can return every cool season, and continuing to apply helps prevent flare-ups.

How to bathe when you have dry skin

Use comfortably warm water, not so hot that the skin turns red.
Bathe for 5–10 minutes and no more than 1–2 times a day.
Use a mild synthetic detergent bar (syndet) or a body wash with a pH of about 5.5, fragrance-free, and use it only where needed, such as the armpits, groin and feet. For very dry arms and legs, plain water is enough.
Do not scrub with a loofah or scrub while the skin is dry and flaking.
Pat the body gently with a soft towel, then apply moisturizer right away.
In an air-conditioned bedroom, do not set the temperature too cold, or use a humidifier to keep humidity at about 40–60%.
Wear soft cotton clothing and avoid wool and synthetic fabrics that irritate the skin.

When dry skin becomes an itchy rash: medicines doctors use

When dry skin cracks into red lines or itches so much that you scratch yourself raw, it means there is inflammation, and a moisturizer alone is usually not enough. The doctor will consider medicines according to the location and severity.

Hydrocortisone 1%: a mild steroid used on thin skin such as the face, skin creases and children. Apply a thin layer 1–2 times a day, for no more than 1–2 weeks.
Triamcinolone acetonide 0.1% cream or ointment: a moderate-strength steroid used for asteatotic eczema on the shins and trunk. Apply twice a day for 1–2 weeks until the redness settles, then go back to a moisturizer alone.
Mometasone furoate 0.1%: applied once a day, used when the rash is thick or extensive, as the doctor directs.
Order of application: first apply a thin layer of steroid only on the rash, then apply a moisturizer over all the dry skin.
Oral antihistamines: sedating medicines such as chlorpheniramine or hydroxyzine at bedtime can help you sleep on nights when the itch is severe, but they do not treat dry skin, and in older adults they can cause dizziness, confusion and falls. Non-sedating antihistamines do little for itch from dry skin.

Signs that the medicine is working: itching eases in 2–3 days and the redness settles in 1–2 weeks. If there is no improvement in 2 weeks, go back to the doctor, because it may be contact dermatitis, a fungal infection or another condition. The choice of steroid, its strength and how long to use it should be decided by a doctor, because using a strong steroid for too long makes the skin thin and stretch-marked. You can read a comparison of each group of topical medicines in Anti-itch creams: how to choose correctly

Is dry skin a vitamin deficiency? What can you eat to help?

In most people, dry skin is not caused by a vitamin deficiency but by the skin barrier and the environment. Taking vitamin supplements when you are not deficient therefore usually does not make the skin more moisturized.

Nutritional deficiencies that can really cause dry skin include vitamin A deficiency, essential fatty acid deficiency, zinc deficiency, niacin (vitamin B3) deficiency, which causes dry, cracked, darkened skin in sun-exposed areas, and iron deficiency, which can cause itching all over. These occur in people who eat very little, drink heavily, have had stomach or bowel surgery, or have a malabsorption disorder, and a blood test should be done before taking supplements.

For most people, foods containing omega-3 fatty acids, such as sea fish, nuts and seeds, are healthy, but the evidence that they help dry skin is limited. Drinking enough water is good, but drinking more than you need does not make skin more moisturized. What clearly helps dry skin more is bathing correctly and moisturizing regularly.

Dry skin in children and pregnant women

Infants and young children: use a fragrance-free ointment or cream, give short warm baths of no more than 5–10 minutes, and avoid high-concentration urea and lactic acid. If there is a red rash on the cheeks or in the skin creases, or itching that keeps the child from sleeping, have a doctor assess for atopic dermatitis.
Pregnant women: dry, itchy skin is common because the skin is stretched. Ordinary moisturizers can be used, but if there is severe itching on the palms and soles, especially in the third trimester, see a doctor promptly to be checked for intrahepatic cholestasis of pregnancy, which affects the baby's safety. See also Itchy palms and soles at night

When to see a dermatologist

You have applied a moisturizer correctly twice a day for a full 2 weeks and the itching or flaking has still not improved.
The itch is so severe that you cannot sleep, or you itch all over with barely any visible rash.
The skin cracks into red lines, or has weeping, yellow crusts, pus, or pain, swelling and warmth.
The skin has been scaly since childhood, or scales have newly appeared in adulthood.
The dry skin started together with other symptoms such as weight loss, night sweats, fatigue, swelling, feeling cold or yellowing of the skin.
Severe dry skin after starting a new medicine, or a rash with blisters and skin peeling in sheets.
You have diabetes and your cracked heels have turned into sores.

A dermatologist will examine you to tell dry skin apart from conditions that look similar, such as atopic dermatitis, contact dermatitis, fungal skin infection, psoriasis and inherited scaly skin, and will order any necessary blood tests if a medical condition is suspected. For an overview of other skin conditions, see All skin conditions

In brief

Dry skin (xerosis) is skin that lacks oils and water-binding substances. It differs from dehydrated skin, which is a temporary condition.
The main causes are dry air, long hot showers, alkaline soaps and age, but dry skin can also come from atopic dermatitis, inherited scaly skin, thyroid, kidney disease, diabetes or medicines.
Choose an ointment or fragrance-free cream, with urea 5–10% for the whole body and 20–40% only for heels or thick skin.
Apply within 3 minutes after a shower, at least twice a day, and apply enough. Bathe in warm water for 5–10 minutes.
Dry skin that cracks into red lines is an inflamed rash and needs a short course of anti-inflammatory medicine as directed by a doctor.
If there is no improvement after 2 weeks of correct care, the itch stops you sleeping, or there are physical symptoms as well, see a dermatologist.

Frequently asked questions about dry skin

What disease causes very dry skin?

Very dry skin is mostly xerosis caused by air, hot showers, soap and age. But if it is so dry that it becomes scaly, cracks into lines, or itches so much you cannot sleep, it may be a skin disease such as atopic dermatitis, ichthyosis vulgaris or asteatotic eczema, and in some people it is a sign of a medical condition such as underactive thyroid, chronic kidney failure or diabetes, especially when dryness has only just started in adulthood together with fatigue, weight changes or swelling. In that case you should be examined by a doctor and may need further blood tests.

What can I do to stop my skin being dry?

Do 3 things together. First, bathe in warm, not hot, water for 5–10 minutes and use a mild soap with a pH of about 5.5 only where needed. Second, apply a moisturizer within 3 minutes after a shower, at least twice a day, choosing a fragrance-free cream or ointment with ingredients such as urea 5–10%, glycerin, ceramide or petroleum jelly. Third, cut back on things that draw out moisture, such as very cold air conditioning, scrubbing and irritating fabrics. Most skin improves in 1–2 weeks. If it does not improve or there is a red, itchy rash, see a doctor.

What vitamin are people with dry skin lacking?

Most people with dry skin are not lacking any vitamin. Dry skin is usually caused by a skin barrier damaged by air, bathing and age. Nutritional deficiencies that can really cause dry skin include vitamin A, niacin, zinc, essential fatty acids and iron, and they are usually seen in people who eat very little, drink heavily or have a malabsorption disorder. If you suspect one, have a blood test before taking supplements, because too much vitamin A itself can make skin dry and flaky. For most people, applying a moisturizer correctly works more clearly than taking vitamins.

How can I tell if I have dry skin?

Try washing your face or showering and then applying nothing for 30–60 minutes. If the skin feels tight, shows fine white flakes, or leaves a white line when you lightly scratch it with a fingernail, it is dry skin. The first places to dry out are the shins, outer arms, backs of the hands and heels. Dry skin differs from dehydrated skin in that dry skin lacks oils and is a regular problem, while dehydrated skin is temporary and can happen even in people with oily skin. If dry skin comes with a red, itchy rash in the skin creases, or scaling since childhood, it may be a skin disease that a doctor should assess.

What should I use for dry, scaly skin?

Dry, scaly skin needs a cream that helps shed scales as well as moisturizing. Commonly used ingredients are urea 10–20% or lactic acid (ammonium lactate) 12%, applied 1–2 times a day after a shower. The scales usually thin out in 2–4 weeks. For very thick areas such as the heels, use urea 20–40% at bedtime. Be careful, as both can sting on cracked skin and should not be used in infants. If the skin has been scaly since childhood or the scaling has newly appeared in adulthood, see a doctor to find the cause first.

Dry skin that itches at night: what should I do?

Apply a heavy moisturizer or ointment every night before bed, set the air conditioner so it is not too cold or too dry, use a light cotton blanket, keep your nails short, and bathe in cooler water in the evening. If the itch is so bad you wake in the night, place a cool cloth on the skin or reapply cream instead of scratching. A sedating antihistamine at bedtime can help you sleep on some nights, but it does not treat dry skin and should be used with care in older adults. If the skin cracks into a red rash, you itch all over without a visible rash, or there is no improvement after 2 weeks of care, see a dermatologist to look for other causes.

Written by Dr. Patara Voravutinon, Dermatologist · Last reviewed 7 October 2026

The information in this article is general knowledge and is not a diagnosis or an individual prescription. The choice of medicine, dose and duration of treatment should be assessed by a doctor.