Seborrheic Dermatitis

My friend has suffered with a skin condition on-and-off for the last four(?) years. Skin conditions are a very difficult condition to research on the internet because the symptoms aren't very specific. If you go to wrongdiagnosis.com you'll see 1143 causes for itching skin, 525 causes for redness, 230 causes for dry skin, etc. In my friends case the affected skin was on her face and was flaky, red and burned.

In my friends case the symptoms started with a small patch on her face around four years ago. She managed the symptoms with OTC topical steroids (hydro-cortisone). Topical steroids are standard treatment where the underlying skin condition is caused by an over-active immune system. They work by suppressing the immune system and constricting blood vessels in the region reducing redness and allowing the skin to heal.

Topical steroids are symptomatic treatments meaning that they do nothing to address the underlying condition that is causing the immune reaction. When the reason for the immune reaction is well known and temporary (think poison ivy) topical steroids are wonder drugs. They suppress the symptoms long enough for the underlying issue to resolve itself.

In her case the underlying immune condition was recurrent and the skin condition would eventually return. Over time it spread from a small patch to covering most of her face. She went from using OTC hydro-cortisone from occasionally, to once every 3-4 days to every day. At this point to maintain control of the symptoms she'd need to use it three times per day. Long term use of topical steroids create their own issues. Skin thins and easily tears, it's easily bruised, stretch marks appear and it can leave the skin red.

After stumbling around Google for a while I stumbled across the condition known as seborrheic dermatitis (also known as seborrheic eczema). I've been working with various search engines since Yahoo was still hosted on the back end of a Stanford University Server. I'm actually pretty good at getting what I need out of search engines which (surprisingly) isn't that common of a skill. Finding specific search terms like seborrheic dermatitis is a major step forward because it allows you to remove a lot of noise from search results. I generally keep Notepad running on my desktop to keep the "good" search terms I've found. I then combine them to drill deeper.

I plugged in "Seborrheic Dermatitis" into Google and found that this was a pretty solid match for the symptoms my friend was dealing with. Going to Wikipedia it tells me that seborrheic dermatitis may be caused by a yeast called malassezia. The yeast is a normal inhabitant of the skin that feed from the fats produced by the skins sebaceous glands. They feed on the saturated fatty acids and excrete the unsaturated fatty acids along with some toxic byproducts. The unsaturated fatty acids and toxins are reabsorbed into the skin where they cause an immune reaction. They even gave a nice link to a study done by Proctor and Gamble where removing the yeast alleviated the symptoms while applying the toxins with fatty acids (without the yeast) induced the symptoms.

There were also a couple of other interesting lines that talked about possible causes. One line said that "In children, excessive vitamin A intake can cause seborrhoeic dermatitis. Lack of biotin, pyridoxine (vitamin B6) and riboflavin (vitamin B2) may also be a cause." There was also a line that said "There is evidence that there is relationship between seborrheic dermatitis and intestinal yeast, such as candida. An antifungal diet consisting of the elimination of sugar should reduce seborrheic dermatitis."

So we have a couple of possible causes. An over growth of a normal innocuous resident yeast that resides on the skin, a vitamin B deficiency and candida (which is a overgrowth of yeast that resides in the gut). Now I had a diagnosis and some leads to a possible cause.

So I started typing into Google things like "candida vitamin B6 deficiency" and "candida seborrheic dermatitis" and started reading. This lead to more specific key words which lead to more specific key words. After reading large numbers of personal posts from people describing their symptoms and the various treatments that work I believe I found an underlying pathway that may explain the underlying cause for a large number of seborrheic dermatitis sufferers.

Candida is a yeast that inhabits the intestinal tract of most all humans. Usually it's harmless and kept in check by friendly bacteria like acidophilus and bifidus bacteria. Candida lives by fermenting sugar which it turns into a potent neurotoxin called acetaldehyde. Acetaldehyde is also produced as a intermediate step in the breakdown of ethanol (the alcohol in beers, wines and liquor) by alcohol dehydrogenase.

Acetaldehyde is eventually converted into acetic acid by aldehyde dehydrogenase but it causes a lot of damage while it hangs around. Activating aldehyde dehydrogenase to metabolize acetaldehyde consumes NAD (the active form of vitamin B3) and zinc. It binds strongly with Acetyl Coenzyme A (the active form of vitamin B5). It binds strongly with P5P (the active form of vitamin B6).

So we have a pretty solid link from candida to vitamin B deficiencies which were listed as possible causes of seborrheic dermatitis. But what's the connection to that yeast called malassezia that was also a pretty solid cause to seborrheic dermatitis?

It also looks like acetaldehyde deactivates something called delta-6-desaturase. To create more delta-6-desaturase the body needs B6, zinc and magnesium. Since acetaldehyde depletes B6 and zinc somebody with a lot of acetaldehyde is going to be deficient in delta-6-desaturase.

Putting delta-6-desaturase into Google provides a link to a very interesting abstract at the National Institute of Health titled Identification of the delta-6 desaturase of human sebaceous glands: expression and enzyme activity. It looks like delta-6-desaturase converts saturated fatty acids to unsaturated fatty acids in the sebaceous glands.

Hmmmm.... So we've got a pathway from candida to to vitamin B deficiencies and we've got a pathway from that to (possibly) excess saturated fatty acid production in the sebaceous glands. And we know that malassezia feeds on saturated fatty acids which could lead to an overgrowth and the inflammation of the skin that we know as seborrheic dermatitis.

Great theory but does it hold up? If it does we'd expect a few things.

• Seborrheic dermatitis should be a side effect of chronic alcoholism since they are getting a lot of acetaldehyde from the metabolism of ethanol. A quick Google search and check! Seborrheic dermatitis is a side effect of alcholism.
• Alcohol should exacerbate seborrheic dermatitis because they would be getting a double dose of acetaldehyde. A quick Google search and check! Personal posts in various forums indicate that alcohol consumption aggravates the condition.
• Infants seem to lack full delta-6-desaturase activity until about six months after birth. We should commonly see seborrheic dermatitis in infants under six months in age. A quick Google search and check! Seborrheic dermatitis in infants is commonly known as cradle cap and "resolves itself in a few months."
  
• Candida often takes over the digestive tract after friendly bacteria are destroyed after a treatment of antibiotics. Many people with seborrheic dermatitis should be able to trace their initial symptoms to a antibiotic course. A quick search of Google and check! It seems that personal posts in various forums show a relation.
  
• Things that clear acetaldehyde from the body should help seborrheic dermatitis. A quick search of Google shows that NAC, B1 and C are supposed to help clear acetaldehyde (hang over treatments). A quick Google search and check! These supplements are commonly listed on threads about seborrheic dermatitis.
• Immune suppressed people are more likely to develop candida. Seborrheic dermatitis should be common. A Google search and check! Seborrheic dermatitis is one of the most common skin manifestations of AIDS.
• Sugar free/low carb diets should reduce the symptoms of seborrheic dermatitis. A Google search and check! "Some anecdotal reports claim that maintaining a low carb diet may improve SD. And check! I've been sugar and wheat-free for a week now and my seborrheic dermatitis has cleared up completely! I had had red patches and scaling all around my face for years now, I've tried all kinds of creams and ointments... I can't believe it.
• Stress depletes B Vitamins so stress should cause flaring of seborrheic dermatitis. A Google search and check! Stress tends to aggravate the condition.

At this point I felt I had a pretty solid case that an underlying candida infection was the source of her problems. It seems that her first outbreak followed an antibiotic treatment for a cough that her doctors thought might be bacterial in origin.

A Google search had turned up some pretty solid treatments for candida (coconut oil, unfiltered vinegar, ThreeLac). It turns out that she'd found that coconut oil and unfiltered vinegar are known as some of the highest rated treatments for seborrheic dermatitis. She'd tried both and had horrible allergic reactions to each (hives, swelling, etc).

That would seem to be bad news but in reality it clinched things. People with candida infections often have bad reactions to anything that kills candida. When the candida die the toxins are released into the body triggering a immune system reaction known as a Herxheimer reaction. The reaction is a sign that she's suffering from a candida infection.

Her next steps will be treating the candida infection. I'll let people know how it goes. Total time invested at this point is about 6 hours of research.