Stress, Worry, Anxiety and Tension are all factors that can affect the production of hormones in the body and this is important because almost all acne is hormonal. There are hundreds of hormones in the body that control and modify all the organ systems including the skin, nails, heart and brain. Basically they are a major influence on your appearance making you look the way you do, feel the way you do, think and function. Amongst this multitude of hormones in your body is a group of them called androgens and they are believed to be responsible for acne. Without getting into too much detail acne results basically from pore lining cells overacting to normal androgens (the cells become inflamed or discoloured)
In most cases living with acne is considered part of growing up and can be accepted as part of a teenager's rite of passage, to be looked back upon fondly as that stage when it was hard to get a date. However such a passive view is being accepted less and less either because of the severity of the flare ups or simply because society is becoming more savvy and is now demanding acne treatment knowing that there is one out there or it could be people are more image conscious and just want to look good and flawless no matter their age. Whatever the reason, the fact remains that acne skin (the most common acne skin is acne vulgaris, a more severe type is acne rosacea) is a problem that if left untreated can impede social advancement in many areas of life.
Though the majority of acne flare ups are hormonal there are other factors that can be held responsible for them too like diet (whatever goes inside you can create chemical reactions capable of affecting the skin on the outside), environment (excessive exposure to the elements -sun, air pollution, dirty water), skin care products there is a good case for extensive testing as not everybody's skin is able to adapt to all the products out there) and the last one is stress.
Stress can act to cause acne by several mechanisms. It can affect the ovaries, testes and adrenal glands leading to release of androgens throughout the body; it can cause direct hormonal changes at the level of the hair follicles; and it can increase the release of inflammatory chemicals, leading to more inflamed acne. Stress can interfere with sleep, encourage poor eating habits, disrupt exercise routines, increase fatigue and decrease adherence to good skincare regimens. A 2003 study published in the Archives of Dermatology (Chiu and Kimball) confirmed that stress can cause changes in the follicles that directly contributes to the formation of acne lesions.
If stress could be one of the factors responsible for acne in this day and age it is no wonder that adult acne is also on the up. Though adult acne occurs for the same basic reason as adolescent acne there is however no clear explanation for the increasing occurrence of adult acne cases.
There are different opinions regarding this; some think that it may be due to subtle hormonal changes that do not appear on standard blood tests, others blame alterations in the responsiveness of the hair follicle, some focus on diet and hormone and antibiotic supplementation of our food sources and finally many suggest that modern life stresses are the main cause.
There is a difference between adult acne and adolescent acne. In the case of adults the lesions tend to be deeper, more cystic and more localized to the centre of the face and jaw line while in adolescents the concentration is more to the forehead and the chin. Another bit of bad news is that the older we get the slower our healing process gets and so this would in a way explain why acne scars are more severe in adults than in adolescents.