Protecting your skin from wind, cold and dry indoor air

Somewhere around November, a lot of Canadians notice the same things: tight cheeks after the shower, knuckles that crack, shins that itch at night, lips that peel. It’s not your imagination and it’s not bad luck. Winter attacks your skin barrier from two sides at once, and once you see how, the fixes are straightforward.

Why winter dries your skin

Your skin’s outer layer, the stratum corneum, keeps water in with a wall of dead cells cemented by fats called lipids. A small amount of water always evaporates through it; researchers call that transepidermal water loss, or TEWL. In controlled climate-chamber studies, that loss goes up as humidity goes down. Dry air simply pulls water out of skin faster.

Now consider a Canadian winter. Outside, cold air holds very little moisture, and wind speeds up evaporation from exposed skin. Inside, your furnace heats that same dry air, and the relative humidity in a heated home often drops below 30 percent. Health Canada’s indoor-humidity factsheet notes that air this dry may aggravate skin allergies, irritate eyes and lead to cracked skin (and static shocks, if you needed confirmation).

Add the winter habits that feel good but strip lipids, such as long hot showers and wool sweaters, and you have a barrier losing water faster than it can repair itself. The Canadian Dermatology Association names cold weather, with its low outdoor humidity and dry indoor heating, as the most common cause of dry skin, and notes it gets worse with age as oil glands slow down.

Fix the air you live in

The one change that helps every part of your skin at once is making indoor air less dry.

• Aim for 30 to 35 percent relative humidity in winter, Health Canada’s recommended range (and keep it under 50 percent in summer to avoid mould).
• Measure it. A hygrometer, a small humidity sensor, costs little at any hardware store.
• Use a humidifier if you’re below 30 percent. Dermatologists often suggest a cool-mist unit in the bedroom, since you spend a third of the day there. Clean it as the manufacturer directs, because a dirty humidifier spreads mould and bacteria.
• Watch your windows. On very cold days, a house may not tolerate even 30 percent without condensation on the glass. If windows fog or drip, turn the humidifier down that day.
• Keep the thermostat moderate. Hotter air is drier air, relatively speaking.

Rethink the shower

It’s the habit hardest to give up, and the one with the biggest payoff.

• Keep showers and baths to 5 to 10 minutes, with warm rather than hot water. Warm water removes the skin’s natural oils more effectively than cool water does, and hot does it faster still.
• Close the bathroom door so the steam stays with you.
• Use a gentle, fragrance-free cleanser, and only where you need it. Traditional bar soap has a high pH (around 9 to 10), which damages the barrier; the Canadian Dermatology Association suggests syndet (synthetic detergent) cleansers with a pH closer to skin’s, around 5 to 7.
• Pat dry rather than rubbing, and moisturize within a few minutes, while skin is still damp.

Move up a moisturizer weight

Whatever you use in July is probably too light for January. Dermatology groups on both sides of the border say the same thing: switch to a heavier cream or an ointment in cold months, because they hold more water in and are less irritating than lotions.

Look for ingredients that do different jobs: humectants that pull water in (glycerin, urea, lactic acid, hyaluronic acid), lipids that fill gaps in the barrier (ceramides), and occlusives that seal the surface (petrolatum). Choose “fragrance-free” rather than “unscented”, which can still contain masking fragrance. The moisturizers filter is a reasonable place to compare.

Winter is also the time to ease off exfoliating acids. The American Academy of Dermatology suggests cutting back on products with alpha or beta hydroxy acids in cold months, as they can be more irritating when the barrier is already stressed.

Apply moisturizer after every shower and every hand-wash, and a heavier layer at night. For shins, elbows and heels, an ointment under cotton socks or pyjamas overnight does a lot.

Hands: the front line

Hands get cold, wind, snow, and then soap and water a dozen times a day. No wonder they crack first.

• Gloves outdoors, always. Cold and wind hit thin hand skin hard.
• Gloves for wet work too. The Canadian Dermatology Association recommends cotton-lined gloves for dishes, cleaning and gardening, so water and detergents never reach your skin.
• A gentle cleanser at the sink instead of a harsh or deodorant soap.
• Hand cream after every wash, kept by the sink and in a coat pocket. A hand care product with petrolatum or ceramides does well here.
• Overnight repair for cracked knuckles: a thick ointment under cotton gloves.

If cracks bleed, won’t close, or you see redness and swelling, see your doctor or pharmacist. Winter hand dermatitis is common and treatable, and it can get infected if ignored.

Lips

Lips have no oil glands of their own, and they take wind straight on, so they chap early. The American Academy of Dermatology’s advice:

• Use a plain balm with petrolatum, ceramides, shea butter or zinc oxide, several times a day and before bed.
• Avoid balms with menthol, camphor, phenol or flavouring, which can irritate and keep the cycle going.
• Outdoors, choose a balm with SPF 30 or more, since snow reflects sun onto your face.
• Don’t lick, bite or pick. Saliva evaporates and leaves lips drier than before.
• Run a humidifier in the bedroom, especially if you breathe through your mouth at night.

Expect a few weeks of consistent care before lips feel normal. If they don’t improve, see your doctor, because persistent chapping can be an allergy or something else.

Clothing and laundry

Wool directly on skin is a classic winter itch trigger. Wear soft fibres such as cotton or silk next to your skin and put the wool on top. Choose a fragrance-free laundry detergent, since fragrance residue in fabric is a common irritant for dry, sensitive skin, and rinse well.

When it’s more than winter

Most winter dryness responds to this routine within a couple of weeks. If skin stays red, cracked, weeping or intensely itchy, or if your usual products suddenly sting, something more may be going on: eczema, psoriasis and some medical conditions all flare in winter. See your doctor or pharmacist rather than waiting for spring.

Winter dries your skin from both sides: cold, thin outdoor air and furnace-heated indoor air that can fall below 30 percent humidity. Fight back on both fronts: a humidifier set around 30 to 35 percent, shorter and warmer showers with a gentle cleanser, a heavier moisturizer on damp skin, gloves for cold and for wet work, and a plain balm for your lips. Do that consistently from November on, and most of the tightness, cracking and itch never gets started.