What causes dandruff, and how do you get rid of it? - Thomas L. Dawson

Summary

Malassezia, a type of yeast living on our scalps, feeds on oils produced by hair follicles, and for about half of the population, its activity causes dandruff. While dandruff is an irritation resulting from skin inflammation, its exact cause remains unclear. Malassezia's consumption of sebum disrupts the skin barrier, leading to excessive skin cell production, which results in visible flakes. Though antifungal treatments can manage dandruff, researchers are investigating genetic factors, skin permeability, and potential benefits of Malassezia's presence. Despite the discomfort it causes, dandruff is not contagious and may even help protect skin from harmful microbes.

Takeaways

• 😀 Malassezia is a type of yeast that lives on the human scalp, feeding on sebum, the oil produced by hair follicles.
• 😀 Dandruff is caused when Malassezia consumes sebum, leaving behind unsaturated fatty acids that disrupt the skin barrier.
• 😀 The body reacts to the skin's damaged barrier caused by Malassezia, resulting in inflammation and an increase in skin cell production.
• 😀 Under normal conditions, skin cells renew every 2 to 3 weeks, but with dandruff, they proliferate too quickly and form visible flakes.
• 😀 Dandruff tends to come and go with variations in sebum secretion, influenced by factors like hormonal changes throughout life.
• 😀 The most effective way to treat dandruff is through antifungal shampoos, which kill Malassezia directly on the scalp.
• 😀 Despite everyone having Malassezia, not everyone develops dandruff. Some people are more susceptible due to unclear factors.
• 😀 Researchers are studying whether people with dandruff have a genetic predisposition or more permeable skin barriers.
• 😀 Malassezia communicates with the immune system through small molecules called oxylipins, which regulate inflammation.
• 😀 Scientists are exploring whether managing inflammation caused by Malassezia could lead to new dandruff treatments.
• 😀 Malassezia helps defend the skin against harmful microbes like Staphylococcus aureus, suggesting some benefits to its presence despite causing dandruff.

Q & A

What is Malassezia and where does it live?

Malassezia is a type of yeast that lives on human skin, specifically thriving on oily areas like the scalp, where it feeds on sebum (skin oils).

Why does Malassezia cause dandruff in some people but not others?

The exact reason is unclear, but factors like genetic predisposition, skin barrier permeability, and individual immune responses may play a role in determining susceptibility to dandruff.

How does Malassezia cause dandruff?

Malassezia feeds on sebum, breaking down the fatty acids. It consumes saturated fats but leaves unsaturated fats behind, which disrupt the skin barrier, causing inflammation, itchiness, and the rapid production of skin cells, leading to visible flakes.

What is the role of unsaturated fatty acids in dandruff formation?

Unsaturated fatty acids, left behind by Malassezia after consuming the saturated fats in sebum, penetrate the skin, disrupt the skin barrier, and cause water loss, triggering inflammation and the accelerated shedding of skin cells that leads to dandruff.

Why is the scalp particularly prone to Malassezia?

The scalp is one of the oiliest parts of the body due to the abundance of sebaceous glands, making it an ideal environment for Malassezia to thrive and feast on sebum.

How does dandruff form at a cellular level?

When the skin barrier is compromised by Malassezia’s activity, the body responds by producing more skin cells in an attempt to repair the damage. These cells don’t mature properly and instead form large, greasy clumps, which shed as visible flakes.

What is the most effective treatment for dandruff?

The most effective way to treat dandruff is by using antifungal treatments, such as shampoos that kill Malassezia and reduce its activity on the scalp.

Why does dandruff come and go for some people?

Dandruff may fluctuate because sebum secretion levels change throughout one's life, often influenced by hormonal changes, which in turn affect the activity of Malassezia.

Are there any potential benefits to Malassezia's presence on our skin?

While dandruff is an uncomfortable condition for humans, some scientists hypothesize that Malassezia helps to protect our skin by defending it from more harmful microbes, such as Staphylococcus aureus.

What is the role of oxylipins in dandruff formation?

Malassezia produces oxylipins, small oily molecules that regulate inflammation. These molecules may play a significant role in the inflammatory response that leads to dandruff, and researchers are exploring ways to manipulate oxylipins to improve treatment.