It might be the bedrock of our locks, but it’s also the root cause of common scalp issues and hair woes.

Dull tresses, flaky skin, and stumped hair growth are all linked to an unhealthy scalp, otherwise known as an imbalanced scalp microbiome.

The scalp microbiome is the forest floor that feeds a healthy head of hair. It’s home to trillions of bacteria, fungi, and other microorganisms that work together to keep hair follicles thriving.

But, just like the skin microbiome, this can easily become out of whack and is particularly vulnerable to certain product ingredients, heat styling, bleach, sun, and pollution exposure.

A compromised scalp can lead to several scalp and hair issues. Here, we reveal the 4 most common.

Common scalp issues from scalp psoriasis to dandruff


Hidden underneath your mane is another secret world working away. Just like the skin microbiome, it’s a smart network that protects you from infection, boosts hair growth, and maintains healthy hair follicles.

Although it’s just next door to your skin microbiome and does share some similarities, the scalp microbiome is more of a moist environment with numerous more sebaceous glands.

This is the perfect environment for skin resident Cutibacterium acnes and explains why our scalps’ tend to be oily. 

When dysbiosis occurs, aka when one microbe becomes more dominant than it should be, it can lead to scalp issues such as dandruff, psoriasis, hair loss, and more.

Earth Day 2023 skin trust club



It’s the pesky condition that creates a mind-consuming itchiness and transforms our locks into a snow globe. Enter, dandruff.

Often pigeon-holed for being an issue for men, it’s actually a condition that 50% of people are predisposed to. And your ancestors could have something to do with it, as research claims it could be down to sensitivities passed down from your parents.

Another common misconception surrounding dandruff is that the clingy flakes are a result of a dry scalp. Or, over-shampooing. But in fact, dandruff is a result of too much oil.

Dandruff is developed from Malassezia yeast – a normal resident of healthy scalps that produces lipids and free fatty acids. 

However, their thirst for sebum can allow it to grow out of control and the more there is, the more it eats. During this process, it releases oleic acid and other inflammatory compounds that lead to further irritation.

In fact, 50% of the world’s population is sensitive to oleic acid, leading to itchiness, redness, and an inflamed scalp.

A dandruff provoker is puberty. As your hormones change, your body naturally produces more scalp oils. Other factors include product build-up, switching shampoos frequently, wearing hats (as this creates a more humid environment), and vitamin deficiencies.

Common scalp issues from psoriasis to dandruff


Affecting anywhere in the body, psoriasis is one of the most common skin conditions. But, according to National Psoriasis Foundation, as many as 45% to 56% of those with psoriasis have it on their scalp.

It’s not too dissimilar to dandruff and its flaking, scaly patches can be easily misidentified. But, unlike dandruff, psoriasis patches tend to be dryer rather than oily. It often has a silvery scale and can be painful, crust up, and bleed.

In recent weeks, ‘What causes scalp psoriasis’ has seen a 250% spike in searches. 

The exact cause of psoriasis, whether on the scalp or elsewhere on the body, is unknown. Although studies believe it is an inherited abnormality of the immune system which leads to inflammation of the skin and joints.

Prosoritiac skin has quicker skin cell growth than normal. Essentially the natural occurrence of shedding the top layer of your skin goes into overdrive. This can be further antagonized by stress, due to the hormone cortisol being released which naturally instigates inflammation.

Although it is not contagious, psoriasis does tend to run in families, with several genes being closely identified with susceptibility to psoriasis.

Other triggers can spur on psoriasis too. These include injuries to the skin such as surgery and sunburns, reactions to specific drugs, and certain types of infections. Respiratory infections like tonsillitis can trigger flare-ups.

Common scalp issues from psoriasis to dandruff


We often view our roots as the window to our hair health. But below that, is the true foundation – the scalp microbiome.

Microbes work to keep your roots strong and healthy. They reside in and around your hair follicle to produce healthy strands and protect both your head and hair from infection. 

When working in equilibrium, both your hair and scalp thrive. When disturbed, hair health is compromised.

Research still remains limited on the exact link between hair loss and an imbalanced scalp microbiome. It’s also important to remember that several other factors can lead to hair loss. 

What we do know is that a disrupted scalp microbiome can provoke inflammation, irritation, and scalp conditions, which can result in hair loss. 

For instance, when pathogenic microbes are able to enter an imbalanced microbiome, they can impact the hair follicles in which healthy hair grows. A 2018 study discovered that the condition of your scalp can stump hair growth as a result of oxidative damage caused when the scalp resident Malassezia grows out of control.

Scalp issues such as dandruff and psoriasis can influence oxidative stress, as well as the normal aging process.

According to this 2021 study, ‘The hair produced from unhealthy scalps can be considered “prematurely aged”’. This is due to a compromised microbiome impacting the hair fibre, leading to more brittle strands.

Common scalp issues from psoriasis to dandruff


A common skin condition, occurring all over the body, is folliculitis. This happens when the hair follicle becomes inflamed and creates red pimple-like spots around the follicle.

Often referred to as ‘shaving rash’, folliculitis arises when bad bacteria are able to enter the microbiome and follicle. Typically a result of a change in the scalp or skin microbiome and skin barrier. 

The bumps can often become sore, itchy, and painful and often take a long time to heal. 

While shaving is a common cause of folliculitis, when occurring on the scalp, it can be triggered by heavy conditioners and potent hair dyes. Both can disrupt the microbial communities and diminish the beneficial bacteria, allowing the bad microbes to enter.

A 2021 study found certain bacterial members to play a part in folliculitis, with one being disruptive skin member Staphylococcus aureus. That’s because a compound it secrets can provoke inflammation in the hair follicles.

Another offender, that we already know to be a friend and foe, is Cutibacterium acnes. This could be due to its ability to clog pores, allowing the combo of sebum, dead skin, and potentially bad bacteria to create inflammation.

Common scalp issues from psoriasis to dandruff


Ensure your Skin Trust Club app is up-to-date and take our survey on the scalp microbiome to discover more about scalp and hair health.

You can also complete the survey here.

Common scalp issues from psoriasis to dandruff

Your skin microbiome report has upgraded!

You now have access to a personalised ingredients library to see what’s compatible with your microbiome, new research-backed information on your microbes, regular skin types and more. You can even learn about the scalp microbiome!

Update the app to find out more, here: iPHONE/ANDROID.

Learn more about your skin microbiome and meet the bacteria living in yours with our skin test. Order here.

Receive Updates

Enter your email below to receive updates from the Skin Trust Club HQ including latest offers and recommendations on new microbiome-friendly products.