What is dandruff? How do I get rid of it? Why does it keep coming back?
Dandruff is caused by a yeast of the Malassezia family, Malassezia globosa to be precise. As a complex, eukaryote cell, creationists superstition insists that it must have been designed by an intelligent [sic] designer. It is also axiomatic in creationism that the only entity capable of designing living organisms is the omnipotent, omniscience god of the Bible, Torah and Quran.
It follows from that then, if we accept the dogma for the sake of argument, that this designer god knew precisely what Malassezia globosa would do and so designed it for that purpose.
And that purpose, apart from making more copies of Malassezia globosa, is to cause the embarrassing condition in humans, dandruff. Dandruff doesn't cause a general illness or handicap (apart maybe from a social handicap), and it isn't even painful, apart from an irritation or itch that needs constant scratching. In fact, inducing the person with dandruff to scratch their scalp a lot is Malassezia globosa's dispersal strategy.
Here is what AI's ChatGPT has to say about it:
Malassezia globosaPerhaps a creationist can explain some other function of dandruff, or, given one of their superstitions, that their creator god created all life on Earth for the benefit of humans, what benefit(s) it conveys to us.
Malassezia globosa is a type of yeast that is commonly found on human skin as part of the normal skin flora. It is considered to be a commensal microorganism, meaning it coexists with humans without necessarily causing harm under normal conditions. However, under certain circumstances, Malassezia globosa can become opportunistic and cause skin conditions. Here are some key points about Malassezia globosa:Please note that my knowledge is based on information available up until September 2021, and there may have been further developments or research findings since that time.
- Role on Human Skin: Malassezia globosa is one of the predominant species of the Malassezia genus found on human skin. It is involved in the breakdown of sebum, which is an oily substance produced by sebaceous glands in the skin. The yeast uses fatty acids present in sebum as a nutrient source.
- Skin Conditions: While Malassezia globosa is a part of the natural skin microbiota, it has been associated with various skin conditions, particularly those that involve excessive sebum production or altered skin barrier function. Some of the skin conditions linked to Malassezia globosa include:
- Dandruff (Pityriasis Capitis): This is a common condition characterized by the flaking of the scalp skin. Malassezia species, including M. globosa, are thought to contribute to dandruff by breaking down sebum into fatty acids that can irritate the scalp.
- Seborrheic Dermatitis: This is a more severe form of dandruff that can affect other areas rich in sebaceous glands, such as the face, chest, and back.
- Malassezia Folliculitis (Pityrosporum Folliculitis): This is a fungal infection of the hair follicles caused by Malassezia species, leading to red, itchy, and pimple-like eruptions.
- Atopic Dermatitis: Malassezia species have been implicated in exacerbating symptoms of atopic dermatitis (eczema) by inducing inflammation and contributing to the breakdown of the skin barrier.
- Research and Studies: Research on Malassezia globosa has focused on understanding its role in skin health and disease. Various studies have investigated the mechanisms by which Malassezia species interact with the skin, contribute to inflammation, and trigger immune responses. Additionally, researchers have explored the potential of antifungal treatments and therapeutic interventions for Malassezia-related skin conditions.
- References:
- Dawson, T. L. Jr. (2007). Malassezia globosa and restricta: Breakthrough understanding of the etiology and treatment of dandruff and seborrheic dermatitis through whole-genome analysis. Journal of Investigative Dermatology Symposium Proceedings, 12(2), 15-19.
- Gupta, A. K., Batra, R., & Bluhm, R. (2004). Skin diseases associated with Malassezia species. Journal of the American Academy of Dermatology, Volume 51, Issue 5, 785 - 798
- Prohic, A., Jovovic Sadikovic, T., & Krupalija-Fazlic, M. (2016). Malassezia species in healthy skin and in dermatological conditions. International Journal of Dermatology, 55(5), e243-e251.
ChatGPT3 "What can you tell me about the yeast Malassezia globosa, with some references?" [Response to user request]
Retrieved from https://chat.openai.com/
That was by way of an introduction to this article by Professor Lorraine Mackenzie, Associate Professor, Clinical and Health Sciences, University of South Australia, and Sean Mangion, a PhD Candidate, University of South Australia from The Conversation. Their article is reprinted here under a Creative Commons Licence:
Lorraine Mackenzie, University of South Australia and Sean Mangion, University of South Australia Dandruff can be dry, like snowflakes, or greasy, with yellow clumps. Up to half of all adults have had this scalp condition at one point, so you’ll no doubt know about these skin flakes and the itchiness.
Dandruff can be embarrassing. It can affect many aspects of people’s lives, such as how they socialise, how they style their hair, and what clothes they wear.
Dandruff is not a modern problem. In fact, it has been around for millennia and was described by Greek physicians. We don’t know for sure whether our ancestors were as bothered by it as much as we are today. But they were interested in what causes it.
What causes dandruff?
Dandruff is mainly caused by the yeast Malassezia. The yeast lives on most people’s skin, either on the surface or in the opening of the hair follicle, the structure that surrounds a hair’s root and strand.
The yeast feeds on sebum, the natural moisturiser secreted by your sebaceous glands to stop your skin drying out. These glands are attached to every hair follicle and the hair provides a dark, sheltered micro-environment ideal for the yeast to flourish.
As the yeast grows, it releases molecules that irritate the skin and disrupts how the skin normally renews itself. This causes the cells to cluster together, appearing as white flakes. When there is excess sebum, this can mix with the cells and cause the dandruff to appear yellow.
The link between dandruff and yeast was made nearly 150 years ago. The person who first identified and described this yeast in 1874 was Louis-Charles Malassez (the yeast’s namesake).
Why do I have dandruff?
As Malassezia is found on most people, why do some people get dandruff and others don’t? This depends on a range of factors.
These include the quality of your skin barrier. This may mean yeast can penetrate deeper if the skin is damaged in some way, for example, if it’s sunburnt. Other factors include your immunity, and external factors, such as which hair-care products you use.
How Malassezia grows also depends on the balance of other microorganisms that live on your skin, such as bacteria.
How do I get rid of dandruff?
Dandruff is mostly treated with anti-fungal shampoos and scalp treatments to dampen down growth of Malassezia. The shampoos most commonly contain the anti-fungal agent zinc pyrithione (ZnPT for short). Other common anti-fungals in shampoos include selenium sulfide, ketoconazole and coal tar.
You can also treat dandruff with scalp masks and scrubs that help restore the scalp barrier, by reducing inflammation and irritation. But as these may not have any anti-fungal action, your dandruff is likely to return.
Home remedies include tea tree oil, coconut or other oils, and honey. There is some evidence to support their use, mostly from studies that show extracts from botanical ingredients can reduce growth of the yeast in the lab. But there is great variation in the quality and composition of these ingredients.
There is also the risk of making the problem worse by providing more oils that the yeast will enjoy, causing more imbalance to the scalp micro-organisms and leading to more irritation.
So it’s best to stick with commercial products.
Why does my dandruff come back?
Your dandruff is likely to return unless the active ingredients in your shampoo can reach the right spot, at the right concentration, for the right amount of time needed to kill the yeast.
Our research focussing on zinc pyrithione-based products showed these shampoos reached the skin surface. But they less-reliably ended up in the harder-to-reach hair follicles.
We found the zinc pythione seemed to target the top of the follicles rather than deep into the follicles.
So this may explain why dandruff keeps on coming back. Your shampoo’s active ingredient may not reach the yeast that causes your dandruff.
We don’t yet know how we can encourage existing formulations to penetrate deeper into the follicles.
What about future treatments?
We’ll likely see new formulations of dandruff shampoos and scalp treatments that better deliver the active ingredient to where it’s needed – deeper into the hair follicles.
We can also expect new active ingredients, such as carbonic anhydrase enzymes. These might target how the yeast grows in a different way to current active ingredients.
We are also beginning to see the development of creams and lotions that aim to boost the health balance of flora of the skin, much like we see with similar products for the gut. These include pre-biotics (supplements or food for skin flora) or pro-biotics (products that contain skin flora). However we have much to learn about these types of formulations.
In a nutshell
Dandruff is annoying, treatment helps, but you may need to repeat it. Hopefully, we can develop improved shampoos that better deliver the active ingredient to where it’s needed.
But we need to strike a balance. We don’t want to eliminate all micro-organisms from our skin.
These are important for our immunity, including preventing more disease-causing microbes (pathogens) from moving in. They also help the skin produce antimicrobial peptides (short proteins) that protect us from pathogens.
Lorraine Mackenzie, Associate Professor, Clinical and Health Sciences, University of South Australia and Sean Mangion, PhD Candidate, University of South Australia
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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