Did you know that in cold, dry air the skin barrier weakens and the skin becomes more reactive?
The skin and the seasons
When winter arrives, many people notice that their skin feels tight, gets dry or itches more than usual. People who already have delicate skin or dermatitis often find that their discomfort gets worse precisely in the cold months.
Doctors have long known that the climate affects the skin. A useful question is why it happens, meaning which mechanisms link temperature and humidity to the health of the skin barrier.
What the review covers
The work we are discussing is a review published in 2016. The authors searched the literature for studies on the mechanisms behind this phenomenon, with attention to people living far from the equator, such as in Northern Europe and North America, where winters are harsh.
The review also explains some terms used in meteorology, such as absolute humidity, relative humidity and dew point. It then looks at the negative effect of low humidity, low temperatures and the different seasons on the skin barrier and on the risk of dermatitis.
What emerges
The authors conclude that low humidity and low temperatures lead to a general decrease in the barrier function of the skin and to greater sensitivity to mechanical stress.
Under these conditions, skin cells release substances that promote inflammation, and some immune cells in the dermis increase in number. As a result, the skin becomes more reactive to irritants and allergens. Published data also show that cold and dry weather increases the frequency and risk of flares in people with atopic dermatitis.
How to read this work
A review lines up many studies and offers a consistent explanation for a common experience. The individual studies differ in methods and populations, and the picture should be read as a whole.
The practical message is that the skin needs more attention in winter. Gentle cleansing, regular moisturizing and care in very heated, dry rooms are sensible habits. If your skin cracks, itches for a long time or a dermatitis gets worse, see a dermatologist.
This article is for information only. It does not replace the advice of a doctor or dermatologist, whom you should consult with any question about your skin.