What causes a dry and itchy scalp?
A study commissioned by Head & Shoulders in 2020 revealed that Brits are much more likely to clean their kitchen surface daily than their hair (66% vs 27%). While this might not sound surprising, your scalp carries 6,000 types of microbes in comparison to your kitchen surface which carries on average 100-300. Then there’s the 2023 study commissioned by Batiste, which found 44% of women avoid exercise to save washing their hair.
So what does this mean? Not all microbes are bad of course – as is the case with most of our bodily processes, a healthy scalp needs good bacteria. However, an overgrowth of bad bacteria can often lead to dandruff, dryness, itchiness and in severe cases, hair loss.
Bad bacteria isn’t the only reason your scalp could be itchy, though it is a major one. Your diet, a skin condition, a lack of filaggrin in your body, addiction to dry shampoo, or even seasonal changes and stress can also come into play. And both an overly dry or overly oily scalp can bring forth a chronic itch while also stunting hair growth. Much like the skin on your face, your scalp boasts a delicate surface that needs to be nurtured – not too oily, but not so cleansed that it’s stripped of moisture and dry – and it’s hard to get the balance just right.
If the itch is just a mild irritation, it’s still worth sorting, especially if you’re working on length retention. Consultant trichologist at the Fulham Scalp & Hair Clinic, Eleanore Richardson, tells GLAMOUR: “As with any skin, if there is any inflammation on the scalp, it will be felt and it will be visible. An unhealthy scalp will not get you the best hair.”
Are dandruff and dry scalp the same?
Dry scalp and dandruff often get lumped together, but they’re actually different issues. “Dandruff is caused by a skin condition called seborrheic dermatitis, which is linked to a yeast called Malassezia that naturally lives on the skin,” says Iris Rubin, MD, a board-certified dermatologist. “For dryness and flaking caused by seborrheic dermatitis, dandruff shampoos, which include ingredients such as ketoconazole, selenium sulfide, salicylic acid, or zinc pyrithione, can be a big help.”
A dry, flaky scalp, however, might be triggered by something else entirely — like contact dermatitis, or a reaction to hair products. With that in mind, treating a dry scalp as if it’s dandruff might not help — and, in some cases, could even make it worse. “If you’re unsure whether your dry, itchy scalp is due to dry skin, seborrheic dermatitis, or contact dermatitis, it’s best to schedule an appointment with a dermatologist,” says Dr. Rubin.
Can colouring my hair affect a dry scalp?
Colouring can be transformative for your overall look, but your scalp might not feel quite as appreciative as you are. According to Issie Churcher, Creative Director at STIL, permanent and semi-permanent dyes often contain harsh chemicals like ammonia, peroxide, and phenylenediamine (PPD). “These ingredients can strip away natural scalp oils, raise the skin’s pH, and slightly damage the scalp’s outer layer,” she explains. “That can lead to mild redness, tightness, tingling and itching.”
To minimise the risk of irritation, Issie recommends a little pre-appointment prep if you’re planning on colouring your hair. “Allow 24–48 hours without washing so your scalp’s natural oils can build up – they act as a protective barrier,” she says. For extra defence, a colourist can apply scalp protection oils or creams before the dye goes on.
Post-colour care is equally important. “Wait at least 24 hours before washing to let your scalp rebalance its natural pH,” Issie advises. “Choose a sulphate-free shampoo it will protect your colour from fading and give your scalp a gentler cleanse.” Her go-to options? Pureology Hydrate for colour-treated hair, or the Shanti Ayurveda Moisture range. And if your scalp is feeling tender after a colour? “Let it settle naturally, and if needed, apply a soothing chamomile lotion.”
Does dry scalp cause hair loss?
Experts agree that while a dry scalp is high unlikely to be the root cause of hair loss, long-term dry scalp issues can may amplify hair loss and hinder hair growth. According to Helen, “dryness can lead to itchiness and scratching, potentially damaging hair follicles and causing breakage or hair loss.” Plus, a scalp that lacks moisture can also affect the overall health of your hair, making it more prone to breakage, split ends and potentially thinning hair.
Scrubbing is generally counterproductive and can lead to further irritation and scalp dryness. If you’re looking to reduce product build-up and get rid of dead skin cells, we recommend using a gentle chemical scalp exfoliants instead. Look for those that contain lactic acid or salicylic acid while steering clear of products with exfoliating beads or particles.
How often should I wash my hair if I have a dry scalp?
Much like dry skin, over-cleansing an already dry scalp can make dryness and irritation even worse. Samantha emphasises that washing your hair every two to three days is often enough as it allows for enough time for your scalp to replenish its natural oils without causing excess oil production. A good rule of thumb is to remember that a dry scalp generally needs less washing that a naturally oily scalp.
So, what ingredients should I look for in a soothing shampoo?
You can first tackle the problem by adding a soothing shampoo that’s specifically made for itchy scalps to your haircare regime. There are a few ingredients you should look out for in your mane care wardrobe:
- Apple cider vinegar has antibacterial, anti-inflammatory and antifungal properties. It’s most appropriate for dry skin. Due to its acidic pH, it’s best used in a shampoo/conditioner rather than being used naked, as that can lead to further drying, which would make the hair follicles more prone to breakage and ultimately making it itchier.
- Peppermint oil can be effective at reducing dandruff and soothing the scalp, in turn calming down any itchiness. Again, restrain from using peppermint oil in its pure form, as it can adverse effects like causing further itching.
- Tea tree oil is another antimicrobial, antifungal and antiseptic oil. It’s resulting anti-inflammatory effects can help reduce or eliminate all sorts of itching as long as it’s diluted in a product.
- Salicylic acid shouldn’t be restricted to skincare. Shampoos containing this BHA are effective at treating itchy scalps caused by psoriasis and seborrheic dermatitis. It also exfoliates the scalp, making it a great haircare ingredient against irritation.
- Moisturising ingredients should also feature heavily in your chosen formula. “Look for scalp moisturising ingredients like aloe vera, which helps to calm irritation and restore moisture; glycerin, which draws moisture from the air to the scalp; and hyaluronic acid — another powerful humectant that deeply hydrates both the hair and scalp,” says Dr. Kapoor. Coconut oil, jojoba oil, or argan oil are also beneficial, since they’re lightweight oils that closely mimic the natural oils of the scalp, helping to restore moisture without leaving a greasy residue.
- Anti-dandruff ingredients like zinc pyrithione or selenium sulfide are commonly found in dandruff shampoos, and can make a real difference if your dryness is causing excessive flaking — or even if the root of your problem is a condition like seborrheic dermatitis.
A version of this story originally appeared on GLAMOUR US.
