As seasons change, so should skin care routines, says Katerina Steventon
Skin condition changes with the seasons, yet the concept of seasonal skin care is still somewhat new to the consumer. The skin is constantly adapting to changes in the external environment that have an impact on skin condition, such as temperature, humidity and solar irradiation. These environmental factors subsequently influence skin biophysical parameters that we can measure (like sebum secretion, transepidermal water loss (TEWL), skin pH) and reflect the integrity and function of the epidermal barrier.
The ebb and flow of the seasonal impact on these parameters is also coloured by cyclical monthly hormonal changes and also subtle, daily (circadian) rhythms that differ respective to specific body sites. However, except for sebum excretion which peaks at lunchtime (and women recognise this as the time when their complexion becomes shiny and they need to reapply make-up), the changes in the other parameters are rather small and masked by external and endogenous influences like seasons and stress.
Summer routines
In summer, higher humidity and temperature influence sweating and higher sebum excretion that leads to more open pores and vasodilation. Skin hydration levels are higher (due to more sweating) but research shows that there is also an increase in TEWL and epidermal thickness during the summer months. Therefore, summer skin care routines require light cleansing and exfoliation to prevent blocked pores and subsequent skin breakouts. It is imperative to avoid cleansing with harsh, foaming facial cleansers that can potentially damage the skin barrier in a humid environment.
Sun damage accounts for 80% of visible ageing, clinically apparent later in life as hyperpigmentation and wrinkling. The essential recommendation is to include daily sun protection in the moisturiser, both UVB and UVA, preventing sunburn and photo-ageing damage, respectively. Sun exposure is also linked to higher lipid peroxidation during the summer months. Layering a higher SPF moisturiser over an antioxidant serum provides better protection. It is recommended to avoid using alpha hydroxy acids and retinoic acid derivatives when in contact with the sun. The use of intense hydration, in the form of an aftersun or a hydrating night serum, facilitates the appearance of even skin tone in terms of texture and colour, and a healthy radiance.
Winter dry skin cycle
In winter, the skin suffers a significant reduction in stratum corneum lipids (ceramides, cholesterol and fatty acids) and in the natural moisturising factor (NMF), leading to an increase in pH and stratum corneum stiffness. These changes often indicate a weaker skin barrier and precipitate the ‘dry skin cycle’, a sequence of events resulting in dry skin. The initial loss of moisture leads to a disruption in the protective skin barrier that initiates a fast repair to the detriment of skin quality. These changes become apparent as visible scaling and redness accompanied with a feeling of tightness in the face. Also, the lower levels of linoleic acid and increased levels of oleic acid might contribute to the formation of comedones and uneven texture during the winter months.
The best preventative measures include preventing exposure to dry and cold winter weather and abrupt temperature changes. In terms of skin care, diligent cleansing avoiding soaps and harsh facial washes, the use of a richer moisturiser and layering of products, including a serum that contains concentrated active ingredients and shows better hydration effect in the short term, would be beneficial.
Transitional times
Spring and autumn represent the ideal time to reassess skin care routines and adjust them to warmer and colder temperatures. Research has shown that low hydration levels in early spring and late autumn are accompanied by low TEWL, indicating a stronger epidermal barrier. It is recommended to alter product usage to lighter/richer textures respectively and change the frequency of exfoliating, mask application and treatments targeting specific concerns. As the exposure to the sun and dramatic temperature changes is limited during these months, lightening and brightening treatments are highly recommended. For example, peels that will intensely exfoliate the skin to counteract hyperpigmentation and uneven complexion can be particularly beneficial.
One brand that has pioneered the concept of seasonal skin care is Elemental Herbology. The award winning British brand promotes natural ingredients and results driven skin care and has a spa line based on the principles of Chinese medicine and acupuncture. Other brands like Pevonia Botanica, a spa product line containing marine and botanical ingredients in technologically advanced formulas, attempt to educate the consumer in editing their skin care routines with the seasons. Both brands guide consumers through seasonal changes by focusing on their skin being healthy, well cared for and well protected all year around.
Regardless of the season, the approach to skin care differs around the world. British consumers, who like simplicity and convenience are partial to cleansing wipes and rich, creamy moisturisers. On the other hand, Americans like more intense cleansing and moisturising ingredients derived from the pharmaceutical industry, while negative perceptions associated with oily skin lead Japanese consumers to double cleanse, further compensating with layering and sophisticated skin care routines. These cultural differences have to be taken into consideration when providing seasonal skin care recommendations.
References
1. Rogers J et al, Stratum corneum lipids: the effect of ageing and the seasons, Arch Dermatol Res, 288(12):765-70 (1996)
2. Nakagawa N et al, Relationship between NMF (lactate and potassium) content and the physical properties of the stratum corneum in healthy subjects, J Invest Dermatol, 122:755-63 (2004)
3. Conti A et al, Seasonal influences on stratum corneum ceramide 1 fatty acids and the influence of topical essential fatty acids, Int J Cosmet Sci, 18(1):1-12 (1996)
4. Le Fur I et al, Analysis of circadian and ultradian rhythms of skin surface properties of face and forearm of healthy women, J Invest Dermatol, 117(3):718-24 (2001)
5. Latreille J et al, Daily variations in skin surface properties using mixed model methodology, Skin Pharmacol Physiol, 17(3):133-40 (2004)
6. Rawlings AV, Matts PJ, Stratum corneum moisturization at the molecular level: an update in relation to the dry skin cycle, J Invest Dermatol, 124(6):1099-110 (2005)
7. http://www.scf-online.com/english/40_e/chronobiology40_e.htm
