This past week I was a speaker on the Autism Summit where I presented relatively unknown information about the connection between skin and autism. No one is talking about this.
Your skin is an amazing, yet underappreciated, organ of the body. It is actually the largest organ in the body and, completely spread out, takes up about 20 square feet. It does far more than just act as a protective barrier, although holding our insides in is a big job in itself. Your skin serves many functions, including that of an organ of elimination, temperature regulator, infection protector, vitamin-D synthesizer, and provider of sensory information to the brain regarding pain, tactile sensation, and pressure. Your skin is also the most visible indicator of the total health of your body and acts as a route of entry for environmental toxicants, the fastest growing area of research related to autism . For all of these reasons it’s a bit of a mystery why it has been left out of discussions relating to autism. But today I am going to illuminate how skin is deeply involved in autism through several mechanisms.
Your skin is directly connected to the brain- this is something I talk about in my book Cracking the Beauty Code: How to program your DNA for health, vitality and younger-looking skin. We sense our world through physical touch which is mediated by a certain kind of neuron. These neurons are found in abundance on your hands. But there is yet another type of nerve, found only under hairy skin, that carries information about our social interactions. These nerves, known as C-tactile (CT) afferents, respond to slow, gentle stroking — the soft touch you’d give to a baby’s forehead or a lover’s arm. And some researchers believe that these fibers are crucial for the development of the social brain and play a role in autism, specifically the areas related to sensory and tactile processing.
These unmyelinated, slow-conduction CT afferents go to a part of the limbic brain, which is where emotions are processed. Children with ASD are characterized by lack of interest in this kind of affective touch. Does this mean the CT fibers in ASD children are somehow involved?
The Journal of Neurological Disorders published a small study in 2016 which reported that the first skin biopsies in children with autism do show loss of C-Tactile fibers by 50%.
Massage therapy specifically directed at tactile abnormalities was shown to be effective in decreasing severity of individual sensory, behavior, and language components of autism as well as severity of autism overall. This opens up touch as a previously unknown avenue of intervention in children with ASD.
This dovetails quite nicely with my personal experience as a mother of hyperactive, inconsolable children. One exasperating night after failing to soothe my infant from his incessant wailing, I intuitively decided to try baby massage. Within seconds of stroking his back, he fell into a coma-like state. I was so astonished that I decided to raise my children (and husband) in a high-touch family from that point on. This is exactly as it sounds, lots of touch, cuddling, abundant affection and love strewn all around, massage as the answer to everything. This illustrates the profundity of touch as absolutely vital to human happiness, health, and social connection. To this day when my now adult children see me, they ask for a massage.
The second obvious connection that skin has to autism is the gut-skin-brain connection. Autism spectrum disorder (ASD) has been separately associated with inflammation/immune dysregulation and gut dysbiosis. But what about a different perspective and possible common mechanisms of action for the gut microbiota and inflammation on the neural basis of ASD?
Accumulating evidence has shown a link between alterations in the composition of the gut microbiota and both gastrointestinal and neurobehavioral symptoms in children with ASD.
Additionally, given the strong connection between gut and skin, we can look at the literature to see what kind of connection to autism has been reported.
Children with autism are 1.6 times more likely to have skin conditions like eczema and children with autism were found to have an odds ratio of 3 x more Atopic Dermatitis.
Looking at it from a different perspective, a large study of 18,000 toddlers looked at Atopic Dermatitis in toddlers under three and did a longitudinal study to see how many developed autism.
The presence of Atopic Dermatitis significantly increased the risk of ASD by almost 9 times. And children from the Atopic Dermatitis group with 3 comorbidities together, namely allergic rhinitis, allergic conjunctivitis and asthma had the greatest risk of developing ASD at almost 17 times! This is huge news and more importantly, suggests that there is a window of opportunity between the diagnosis of Atopic Dermatitis and ASD in which certain preventive therapies could be put to the test.
For example, what about probiotics? Probiotics have been shown in the literature to improve skin conditions such as Atopic Dermatitis by influencing the microbiota.
Probiotics have been shown to help with regularity, immune health, skin issues, mental health and we are at the beginning of the research. Probiotics will be integral to the conversation on the gut- skin- brain connection.
Finally, the skin is an exposome, an underappreciated route of entry for all the environmental exposures a person will have over their life time. Do you know that the skin permits many environmental chemicals to get into the body? Think of the skin as a semi-permeable membrane, not body armour designed to keep out everything.
A number of environmental agents have been suggested as contributing factors to ASD, including certain heavy metals such as mercury and lead, persistent organic pollutants such as DDT and PCBs, which were both banned since the 1970’s but are still found in the environment, air pollution, pesticides, and emerging chemicals of concern such as Bisphenol A (BPA) and phthalates. Ingestion, like consuming mercury via fish, or direct application, like applying personal care products to the skin, aren’t necessary- even passive exposure to agents, like walking through an area with air pollution, can lead to the skin absorbing these chemicals.
An analysis of National Health and Nutrition Examination Survey data from 2003-2004 found that virtually every pregnant woman in the United States was exposed to at least 43 different chemicals. And some of them like methyl mercury can accumulate in the fetus in higher amounts than in the mother. In other words, instead of protecting the fetus from noxious environmental exposure, the placenta can concentrate it in the fetus. The 2008-2009 President’s Cancer Panel Report observed that “to a disturbing extent babies are being born ‘pre-polluted’”. Additionally, the chemicals that were found in cord blood include the very ones mentioned above as contributing factors to ASD.
Some of these chemicals, like BPA and phthalates, are found in consumer and personal care products and find their way into the body through dermal absorption. It is critical to avoid them, especially for those women wishing to conceive, or those who are pregnant or breastfeeding. And this extends to personal care products used in and around the babies as well such as diaper cream, wipes, shampoo, body lotions, and more.
So there you have it- the skin is involved in autism via 3 different mechanisms. First of all, the CT afferents that connect touch to the limbic system in the brain appear to be different in ASD children, leading to a potential intervention with touch therapy. Secondly, there is an association with Atopic Dermatitis, other allergic problems, digestive issues, and autism that lend itself to intervention with probiotics. Finally, the skin is an underappreciated route of entry for toxins, and this is an area that is easy to get around once you know what products to avoid. Knowledge is power!