It is easy to think of the skin's role in our immune system as just a simple barrier that keeps good things in and bad things out. And while it does that, there is much more to it. Our largest organ plays an active role in our immune system and houses our skin microbiome, which has far reaching effects on our health. Maintaining healthy skin is crucial to a healthy immune system, and vice versa.
Numerous white blood cells, the soldiers of our immune system, reside in the skin ready to respond to intruders like bacteria that do not belong, or insults/injuries that could be a threat, like a cut or a burn. The keratinocytes, the cells that give the skin structure, also participate in the immune response. When there is an intrusion, these cells are able to call in backup by mobilizing a body wide response. To work their best, these cells need a hospitable home in well hydrated skin. This hydration is maintained by sebum produced by glands in the skin, in addition to the natural moisturizing factor (NMF) produced by the keratinocytes.
"Our largest organ plays an active role in our immune system and houses our skin microbiome, which has far-reaching effects on our health. Maintaining healthy skin is crucial to a healthy immune system, and vice versa."
As you may have suspected, there are many factors that influence skin hydration, only some of which can be controlled. Both sebum and NMF production decrease with age and can be influenced by hormone fluctuations, diet and stress. NMF levels are also decreased by certain medications, as well as in diseases like psoriasis or genetically in the case of atopic dermatitis. Sun exposure and low humidity also reduce NMF levels.
There is also a delicate balance between the organisms that live on our skin (our skin microbiome), our immune system, and our skin hydration, and they all influence one another. Alterations in the usual diversity of the skin microbiome can result in flares of atopic dermatitis, acne, psoriasis and rosacea. The ravages of inflammation in the skin related to these conditions further exacerbates loss of hydration in the skin, which makes the skin more vulnerable to intruders activating the immune system and perpetuating the cycle.
So, what can you do to keep your skin immune system and microbiome functioning optimally?
Avoid over-washing and over exfoliating the skin. Select cleansers appropriate for skin type that are pH balanced, and avoid antibacterial soaps. Look for moisturizers with hyaluronic acid, ceramides, amino acids and fatty acids. Protect the skin from ultraviolet light exposure. Eat the rainbow to ensure your immune system cells have the vitamins and minerals needed for optimum function. Get adequate sleep, because immune system function is reduced without time to repair during sleep. Exercise to help your immune cells get where they need to go through increased circulation. Minimize stress with meditation, exercise, or any self care activity that brings joy. Drink plenty of water.
No organ in the body functions in isolation. Focus on overall health and wellness for supple well-functioning skin and a healthy immune system.