Dermatitis is a condition many pets suffer from. This article explains the importance of addressing your pet's digestive system to resolve dermatitis.
Leaky skin (the external epithelium) is connected to leaky gut (the internal epithelium). Often, leaky gut first presents as skin issues, and the most common example of this in clinical practice is atopic dermatitis (AD).
In a healthy state, our skin provides protection, temperature regulation, and maintains hydration. It is constantly renewing and regenerating itself with epidermal turnover. Genetic, immunologic, microbial, and mechanical factors contribute to skin barrier function. When the skin’s barrier is damaged or out of homeostasis, it no longer can function as designed, leading to leaky skin and appearance of a number of diseases, including acne, psoriasis, ichthyosis, and eczema.
Leaky gut and leaky skin share some key similarities that impact overall health. Leaky skin is not as efficient as healthy skin at keeping allergens out, so they cross the epithelial barrier and trigger a systemic immune response. An impaired epidermal barrier also makes it more likely to absorb potentially hazardous chemicals, which might cause reactions in the skin (contact dermatitis) or systemic toxicity.
Skin forms a protective barrier that limits external invasion and provides a natural habitat for a multitude of microbes (bacteria, fungi, viruses), called the skin microbiota. Microbes colonizing the skin support the skin’s barrier function. There is diminished bacterial diversity in AD and elevated amounts of Staphylococcus aureus (S. aureus) are detectable on AD skin, which negatively impacts the skin barrier function.
The skin’s barrier function is dependent upon the structure and composition of the uppermost layer of the epidermis, the stratum corneum (SC). Lipid organization and lipid metabolism in the SC requires an acidic pH, and when this is out of balance it can contribute to the issues of skin barrier function seen in atopic dermatitis.
Use of harsh alkaline detergents in skincare products may increase the skin’s natural pH and trigger inflammation. A leaky epidermal barrier, causing water loss from the skin and causing dry skin, further predisposes skin to microbial imbalances. Achieving a well-balanced skin microbiota protects skin from harmful pathogens and promotes the natural lipid barrier and skin’s immune system. Ultimately, this function helps prevent AD and other skin conditions.
Conventional treatments for AD often miss addressing the underlying causes, and overzealous hygiene routines worsen the tissue. Antibiotic prescriptions are common in dermatology, and excessive use of antibiotics has created an emergence of “superbugs.” With a natural approach to AD, we want to support a healthy microbiome and restore the skin’s hydration and pH to improve skin barrier function. The most effective approach occurs when we address these both internally and externally.
Improvements to the internal epithelium often leads to improvements on the external epithelium, so it is important to address leaky gut. Overall probiotics have shown to be beneficial. Probiotics are known to enhance positive gut microbiota changes, and a great place to start is the diet, with fermented foods, such as kimchi, sauerkraut, pickled produce, yogurt, and kefir. Fiber-rich and prebiotic foods can help promote the growth of probiotics – dandelion greens, onions, leeks, and chicory.
Probiotic supplementation has been shown to help prevent and treat AD. In the research, species of Lactobacillus and Bifidobacterium are the probiotics showing the highest potential for the treatment of AD. It is important to consider the strength, quality, and duration of probiotic supplementation and that an individualized approach works best (when buying probiotics make sure they are micro-blended with a mineral rich food because without minerals probiotics will not populate in the gut efficiently).
With AD comes an impaired barrier and inflammation of the skin plus an increase in the pH of the epidermal surface. This elevated pH further triggers inflammatory cytokines and comprises the barrier function and increases the chances of infection. The mildly acidic normal SC inhibits the growth of S. aureus and Streptococcus pyogenes, so that the normal flora can thrive, like Staphylococcus epidermidis and Corynebacterium. So, the pH of routine skincare products as well as topical treatments should be in these 4.5 to 5 pH ranges.
Restoring optimal pH helps support the skin’s hydration. In addition, certain topical ingredients can help restore water loss. However, common moisturizers are known to worsen AD since the skin barrier is already compromised, and with leaky skin it is important to avoid toxic chemicals that can more easily find their way into the bloodstream.
What is applied to the skin can impact the skin microbiota, which is essential in addressing AD. Topicals commonly known to create imbalances include antibiotics and antimicrobial ingredients like triclosan. Occlusives (such as dimethicone, petrolatum or lanolin) are commonly used in AD, but since they are trapping moisture in, they do not allow the skin to breathe. The concern is that when moisture is trapped in, especially when the person perspires, it can potentially disrupt the skin microbiota.
Humectants (such as glycerin) pull water in from the surrounding area. These can be helpful, especially during dry winter months and after overzealous hygiene practices when AD typically flares. Ceramides in skincare are often more marketing hype than designed for efficacy. For these to be effective, there needs to be the correct physiologic lipids at an appropriate ratio, or the barrier function may deteriorate rather than improve.
Coconut oil is my favorite topical oil for AD and an excellent base for natural lotions and cleansers for people with AD (best brand is Artisana). It contains lauric acid, which is known to have antimicrobial and anti-inflammatory effects, and it has been shown to positively impact the skin barrier. In a study of 117 children with mild to moderate AD, the topical application of 10 ml. of virgin coconut oil for eight weeks was found to reduce the severity of AD by about 30% more than mineral oil.
Topical use of sesame seed oil also shows some promise in reducing the need for children with AD to use topical corticosteroid treatment. I recommend avoiding olive oil because it has been shown to worsen AD.
Certain extracts of botanicals have shown some promising results in the research with topical applications, including St. John’s wort, licorice extract, willow bark, gentian as well as topical use of evening primrose oil. Topical use of manuka honey has been shown to inhibit S. aureus proliferation and reduce inflammation and shows promise in managing AD. Any of these can be included in a topical made by a compounding pharmacy.
To summarize a naturopathic approach, I want to stress the importance of addressing AD both internally and externally. Internally, we want to focus on healing leaky gut and addressing gut dysbiosis. We also want to address nutritional deficiencies common with leaky gut, such as vitamin D. Externally, our goal is to restore the skin’s pH, microbiota, and lipid barrier to repair leaky skin. While AD typically takes time to heal, when you use this internal and external approach simultaneously, the healing will allow for not only short-term but also long-term result.
Townsend Letter – April 2021, pgs. 46-47.
Donia Alawi, Organic USA