The Skin Microbiome and Lupus

The microorganisms on the skin, known as the skin microbiome, effects the health of people with lupus, both in terms of vulnerability to infection and in inflammation.

Bacteria play an important role in the human body, particularly in the intestines where they help break down food and produce certain vitamins. In the last 20 or so years, people have become increasingly aware of how the gut microbiome is affected by diet, and how intentionally eating foods rich in “good” bacteria can dramatically improve one’s health. In particular, how encouraging “good” bacteria to move into the gut can help make the immune system function healthier. You can read more about lupus and probiotics, here. In general, the more diverse the microbiome is, the better.

However, good bacteria are not limited to the inside of the body. The bacteria, yeasts, viruses, and other microorganisms living on our skin are also important to our health.

What is the Skin Microbiome?

The skin is an organ that protects the body from foreign organisms, so it is fairly resilient and has many features (high acidity and salt content, dryness, and lack of nutrients) that help it block invaders. Many bacteria find it a less-than-pleasant environment, but some bacteria have adapted to live in this space. The skin actually varies between different parts of the body with different levels of sweat, textures, folds, moisture, oxygen exposure, and oil production. This effects the microbiomes on the skin, with different microbes favoring different spots on the body. For example, bacteria that are associated with acne like oil and the texture of facial skin.

This fact, in addition to the constant exposure of the skin to the outside world, would normally result in a diverse and rich ecosystem on the body. To a certain degree, the microbiome on our skin does similar things to the microbiome in our intestines. This includes producing substances that help maintain the health of the skin and its ability to repel invaders.

These organisms also crowd out those that can make us sick, preventing them from getting a foothold on the skin. The skin microbiome also effects body odor. Such as armpit smell among others. If you know someone with bad body odor, the skin microbiome (which interacts with the chemical composition of their sweat) may be the culprit!

The skin microbiome can be affected by a person’s environment, the body’s overall health, the immune system’s health, and certain medications. Hormone differences between sexes also effect the microbiome, and ethnicity seems to also have some effect (though the exact reasons for this are unknown). Hygiene and cosmetic use also can change the skin microbiome, which you can read more about here. The skin microbiome also changes naturally as a person ages. 

Skin Microbiome and Lupus

When tested, the skin microbiotia in people with lupus is very different from healthy controls. The studies found, further, that the less diverse, populous, and evenly distributed the microbiome was, the more intense lupus symptoms (including kidney symptoms) are present.

People with lupus experience more bacterial infections than otherwise healthy people. Staph, in particular, is a leading cause of infection in people with lupus. Staph infections are linked to serious conditions including necrotizing fasciitis (although there are other bacteria that can be involved) a devastating flesh-eating infection that can also infect people who are on immunosuppressants.

People with lupus have less-diverse and less-densely populated microbiomes than otherwise healthy people, as determined by some studies. Lupus lesions, when tested, have very different microbiomes than the rest of the skin. One bacterium in particular is Staphyococcus aureus, the bacteria responsible for staph infections. About 40-50% of their skin was colonized by staph bacteria, compared to 30% in people who do not have lupus. Staph can be present on the body long before it invades. It also may trigger inflammation or flares just by being on the skin. Since the skin cells can detect it and will release interferon, summoning the immune system to deal with the bacteria before it causes an infection.

The interferons released by these skin cells help the staph bacteria “stick” to the skin. The interferon seems, specifically, to break down some of the barriers between skin cells and the outside world. Reducing the toughness of the cells. It is thought that this allows the bacteria to get a foothold.

What is Cutaneous Lupus?

Cutaneous lupus erythematosus (CLE,) is a form of lupus that primarily effects the skin. Symptoms include rashes, sores, and disk-shaped raise blotches on the skin (discoid lesions) and can appear on the face, ears, neck, arms, legs, and hands. CLE can occur alongside systemic lupus erythematosus (SLE) or on its own. Though people with CLE and SLE both suffer from sunlight sensitivity. People with CLE can actually see their symptoms intensify with light. You can read more about light sensitivity and lupus here.

Treating SLE also treats CLE, so corticosteroids, NSAIDS, and immunosuppressants can help with CLE. However, CLE can also be treated with medications that are applied on the skin, known as topical medications. Sunscreens are particularly important, as they both moisturize the skin (which prevents irritation) and protects against sun exposure. This can prevent CLE symptoms from developing. Numbing, cooling, or pain-relieving lotions – such as those made with aloe – help people with CLE avoid scratching, squeezing, or picking at cutaneous lupus lesions, preventing them from getting worse.

Lupus Treatment and the Skin Microbiome

Although the microbiome is resilient, lupus and the medications can change things for the worse. Sometimes, the microbiome on the skin, just like in the gut, needs a little help. There are many ways for people to treat itchy skin and rashes, some of which help “feed” the skin microbiome as well as moisturize. Essential oils (properly applied) and natural skincare products may help soothe the skin and support development of the skin microbiome.

Skin microbiome transplants are also possible. By sterilizing the skin with antibiotics, the skin can then be re-colonized with selected microbes and nutrient supplements. However, this can be tricky as certain favorable bacteria might not be able to thrive in their new environment. Like with other microbiome transplants, using antibiotics on the skin can also be harmful, and can actually clear the way for harmful bacteria. This is definitely only an option in last-resort cases, or after antibiotics are used for another purpose.

Speaking of which, topical antibiotics can be used to treat and prevent infections such as staph. Cosmetics are useful for people with cutaneous lupus, since they can cover up the lesions. However, certain cosmetics can be formulated to actually have an effect on the microbiome of the skin. They can be fortified with probiotics (favorable bacteria), prebiotics (nutrients that encourage the growth of certain favorable bacteria), and “cosmeceutics,” which are designed not to harm the current balance of the microbiome.

All of these could potentially be helpful for people with lupus — but always be sure to consult your lupus treatment team before starting any new treatments. And, consider adding a dermatologist to your team to better manage the skin challenges of lupus.