Skin Dryness (Xerosis): Causes and Treatment

What happens in dry skin

The outer layer of skin (stratum corneum) works like a brick wall: skin cells are the bricks, and fats such as ceramides, cholesterol and fatty acids are the mortar. This barrier keeps water in. When the fats are washed away or not made in sufficient amounts, water escapes, and the skin becomes rough, tight, flaky and itchy. Cracks let in irritants and germs.

Signs of dry skin:

• tightness after bathing
• rough, dull or ashy-looking skin
• fine flaking or scaling
• itching, often worse at night
• fine lines or a "crazy paving" pattern of cracks, especially on the shins (eczema craquelé)
• deep, painful cracks (fissures) on heels and fingertips

Everyday causes

• Low humidity: cold winter air outside and heated air indoors.
• Hot water and long showers: dissolve skin fats.
• Soaps and detergents: alkaline bar soaps, antibacterial soaps, and frequent handwashing or hand sanitizer.
• Age: oil and sweat production decline after about 60, so most older adults have some xerosis.
• Occupation: healthcare, food service, cleaning and hairdressing involve constant wet work.
• Swimming: chlorine dries skin.
• Sun damage: makes skin rough and thin over time.

Medical causes

Medicines that dry the skin include retinoids (isotretinoin for acne), diuretics, statins, some cancer treatments, and topical acne products.

Dry skin vs eczema

Dry skin feels rough and may itch, but it is not usually red or inflamed. Eczema is an inflammatory condition: dry skin plus red, itchy, sometimes weeping patches, often in elbow and knee creases. Very dry skin can tip into eczema, especially on the shins of older adults (asteatotic eczema). If moisturizer alone does not settle red, itchy patches, a short course of steroid cream may be needed.

How doctors assess dry skin

Most dry skin is diagnosed by looking at it. A doctor asks about bathing habits, products, work, medicines and family history. If dryness is severe or unexplained, blood tests may check thyroid function, blood sugar, kidney function and iron. A skin biopsy is rarely needed.

Treatment and self-care

Moisturize correctly

• Apply a thick, fragrance-free moisturizer within 3 minutes of bathing, while skin is still slightly damp, to trap water.
• Ointments (such as petroleum jelly) are the most effective; creams are a good balance; lotions are lighter and less effective for very dry skin.
• Look for ingredients such as ceramides, glycerin, urea, lactic acid or shea butter. Urea and lactic acid also soften thick scale, but can sting cracked skin.
• Reapply through the day, especially on hands after washing.

Change bathing habits

• Limit showers to 5 to 10 minutes with lukewarm water.
• Use a gentle, soap-free cleanser, only where needed.
• Pat skin dry rather than rubbing.

Protect your skin

• Use a humidifier in winter, aiming for 40 to 60% indoor humidity.
• Wear gloves for dishwashing, cleaning and cold weather.
• Choose soft, breathable fabrics such as cotton; avoid wool directly on skin.
• Use fragrance-free laundry detergent.

For cracked heels and fingertips

Soak for 10 minutes, gently file thick skin, then apply a urea-based cream and cover with cotton socks or gloves overnight. Liquid bandage can seal painful cracks.

Medical treatment

Prescription creams with higher urea or lactic acid concentrations, short courses of steroid creams for inflamed patches, and treatment of an underlying condition such as hypothyroidism. Ichthyosis needs ongoing specialist skin care.

Frequently asked questions

What causes extremely dry skin?

Usually a combination of dry air, hot showers, soap and aging. Extremely dry skin that does not respond to moisturizer can be due to eczema, ichthyosis, psoriasis, an underactive thyroid, diabetes, kidney disease or medicines such as isotretinoin. A doctor can check for these.

Can dry skin be a sign of a medical condition?

Yes. Hypothyroidism, diabetes, chronic kidney disease, Sjogren's syndrome, nutritional deficiencies and inherited ichthyosis can cause dry skin. These usually come with other symptoms, such as tiredness, thirst, or dry eyes and mouth, which help point to the cause.

What is the best treatment for very dry skin?

A thick ointment or cream applied right after bathing, short lukewarm showers with a soap-free cleanser, and a humidifier. Products containing ceramides, urea or lactic acid help. If skin stays dry or becomes red and itchy after 2 weeks, see a doctor.

Does drinking water help dry skin?

Drinking water helps if you are dehydrated, but extra water does little for dry skin in most people. The main problem is water escaping from a damaged outer barrier. Moisturizing and gentle washing make a much bigger difference.