1.How does the stress response affect skin? One of the most important effects of stress on skin is the changes to the skin barrier function. Psychological stressors upregulate the hypothalamic-pituitary-adrenal axis to stimulate local and systemic stress hormone production. Psychological stress is well known aggressor in inflammatory dermatoses associated with skin barrier dysfunction. Psychological stress causes the release from the hypothalamus of corticotropic releasing factor (CRF). This substance (CRF) releases pro-inflammatory mediators. Stress also causes what is referred to as neurogenic inflammation that causes, itching, flushing and swelling. Often patients tell me the minute they get stressed in a meeting their skin becomes itchy and irritated so they start to itch – the so-called itch scratch cycle that can be difficult to break.
I often see a ‘stress patch’ on skin, commonly on the back of the neck or forearm where there is an itchy patch of thickened skin. When the individual gets stressed, this area immediately itches, it is scratched the skin thickens and becomes more irritated developing what is called lichen simplex chronicus. Unless this patch is rigorously treated by using anti-inflammatory creams and preferably covered to make it difficult to scratch it will not settle.
Studies have also shown a reduction in skin surface lipids such as fatty acids, ceramides and cholesterol that form an important protective layer to reduce trans-epidermal water loss. A dry inflamed skin barrier is going to be vulnerable to infection, irritation and an exacerbation of inflammatory dermatoses. It is clear to see how therefore stress manifests in skin issues
2. How does stress disrupt the natural cortisol curve? We have a natural diurnal variation in cortisol. Cortisol is normally at its highest 30 minutes after waking up. It steadily declines during the day, until its lowest point just before bed. With Chronic stress cortisol levels are elevated throughout the day leading to feelings of exhaustion ,anxiety and insomnia .
3. How does stress manifest on the skin? There has long been accepted a clear association between stress and an exacerbation of dermatoses such as psoriasis, eczema and acne. One of the clearest manifestations of stress and skin is the effect on the skin barrier as discussed above. The mechanism for stress and an exacerbation of inflammatory dermatoses such as eczema and psoriasis and its associations with skin immunity and barrier function makes sense. The relationship in acne is more complicated. Here it seems to be a cumulation of issues. We know that the oil producing glands have receptors for the stress hormone cortisol. Remember however acne is an inflammatory skin condition and stress is pro-inflammatory. Stress can exacerbate unwanted habits such as skin picking that will inflame acne. It is clear therefore why some studies suggest up to 80% of acne sufferers feel stress exacerbates their skin.
4. Aside from its direct impact, can you talk to its other effects that an overexposure to cortisol has on the skin? When we are stressed, we often make poor lifestyle choices and are more likely to smoke, drink alcohol eat unhealthy foods and take less exercise, all of which are pro-inflammatory and exacerbate an already stressed skin. There is a lot of interest currently around the so-called brain-skin-gut axis. This intimate link was identified as far back as 1930 when Stokes and Pillsbury attributed depression to altering the gut microbiome, leading to inflammatory skin diseases
In 2016 O’Neil et al (1) published a review looking at the mechanisms linking the gut and skin health. One of the associations is through the microbiome. Although not fully explored, the gut microbiome appears to influence the skin though its effect on immunity. There may also be a more direct effect, gut bacteria and their metabolites have been found in skin; a suggested mechanism that a disturbed intestinal barrier can allow gut bacteria to leak into the blood and directly accumulate in skin.
Stress directly affects gut health and increasingly we are aware of an intimate relationship between the gut, skin and brain. By optimising the health in these areas ie. Reducing stress, promoting a healthy gut we can optimise skin barrier function and skin health. There is increasing work being done looking at this symbiotic relationship.
5. In skincare what actives or ingredients should we be looking at to deal with the impact of stress? The first obvious step is to attempt to strengthen the skin barrier. Ideally one should look for a combination of soothing and hydrating products to calm and protect skin. Stressed skin with its vulnerable skin barrier is easily irritated. Choose a gentle hydrating cleanser, the right cleanser is the most important step when there is skin barrier dysfunction. After cleansing I recommend applying a hyaluronic acid followed by a moisturiser that ideally will combine a humectant to hold water in the skin barrier. Look for soothing ingredients such as niacinamide, azelaic acid, panthenol and allantoin . Increasingly there are creams that look to replenish a healthy microbiome which also makes sense. Antioxidants are important to reduce oxidative stress in stressed skin. The antioxidants I recommend include vitamin C , resveratrol ,anthocyanins and green tea.
References:
(1) O’Neill CA, Monteleone G, McLaughlin JT, Paus R Bioessays. 2016 Nov; 38(11):1167-1176.
