In the Judeo-Christian Bible, the book of Ecclesiastes famously cites that “to every thing, there is a season.” However, the scriptures, and subsequent mega rock hit by The Byrds, conveniently left out the season for bad skin. After all, it’s not easy finding a good word to rhyme with eczema. Thankfully, science has taken notice these seasonal skin changes, and new evidence from investigators at the University of Copenhagen might just have a bead on what is happening at the cellular level to allow these changes to occur.
For many people who live in northern latitudes with winter seasons, the risk of developing forms of dermatitis are increased due to decreased temperatures and humidity. Previous studies found that a deficiency in a natural moisturizing factor (NMF) was closely associated with previously unidentified nanoprotrusions on corneocytes, cells in the outermost part of the skin's epidermis. The researchers in the current study looked to “investigate the effect of season on NMF levels and corneocyte surface texture in cheek and hand skin of healthy adults.”
In tests of skin on 80 adults (40 men and 40 women), the levels of breakdown products of filaggrin—a protein that helps maintain the skin's barrier function—changed between winter and summer on the cheeks and hands. Moreover, the research team saw that in cheek skin for the participants, NMF levels were reduced and dermal texture index (DTI) values were elevated during the winter compared with the summer. Interestingly, older participants had higher NMF levels than younger participants.
"This study shows clearly that the skin barrier is affected by climatic and seasonal changes,” explained senior study investigator said senior author Jacob Thyssen, M.D., Ph.D., professor in the department of dermatology and allergology at the University of Copenhagen. “Both children and adults suffer from red cheeks in the winter in northern latitudes, and some may even develop more permanent skin conditions such as atopic eczema and rosacea. By the use of high magnification, we show that the skin cells suffer from shrinkage and therefore change their surface. The clinical message to individuals are that they should protect their skin with emollients in the winter and sunscreen in the summer.”
"We already know that humidity can affect the texture of the skin and impact on skin disorders like eczema, and humidity fluctuates according to season,” commented Nina Goad, who was not directly associated with the study and is head of communications at British Association of Dermatologists. “In the winter, rapidly changing temperatures, from heated indoors to cold outdoor environments, can affect the capillaries, and prolonged exposure to wet weather can strip the skin's barrier function. This latest study is interesting as it sheds new light on further reasons for seasonal skin changes, at a cellular level. Given that skin problems are the most common reason for people to visit their doctor, any research that improves our understanding of skin disorders and how best to manage them is always a positive step."