A trichologist guide to Dry Scalp

Scalp dryness, next to scalp itchiness and flaking, completes the ‘big three’ circle of problematic conditions most commonly experienced by people. Whilst not always the case, it isn’t uncommon that complaints about dryness will accompany ones about itchiness and or flaking. In this post, we’ll give insight into what a dry scalp is, its causes, and how to remedy and prevent it.

The difference between dry scalp and dandruff

Before we get into the heart of the matter, it’s worth noting the difference between dry scalp and dandruff. Both of these conditions share some similarities and so naturally are often deemed synonymous with one another - but this is not the case.

For example, in both cases, the person experiencing either of these conditions is likely to find that it is accompanied by itching and flaking. In the case of dandruff, however, flaking and itchiness are a result of excessive oil production, as opposed to skin irritation from dryness. Understandably, flakes from dandruff are usually larger and more oily than those from scalp dryness, which are smaller and more dry/powdery. Furthermore, except where triggered by an allergic reaction to a product, scalp dryness is rarely limited to the scalp. It is more likely that the dryness will also present on other parts of the skin. This isn’t the case with dandruff. Some treatment methods used for controlling dandruff and seborrheic dermatitis can aggravate dry scalp and vice versa, so discerning the difference between the two conditions is key to choosing the most appropriate and effective treatment.

What causes a dry scalp?

Scalp dryness can be triggered by a range of factors, most of which can be categorized either as internal factors (i.e. as a result of things going on within the body) or external and environmental factors (i.e. triggers from outside the body).

Internal causes

Genetics: One of the first causes of dry scalp. Scalp dryness can occur due to certain genetic factors, one of which is lower than average sebum production. Sebum is the body’s natural oil, secreted by the sebaceous glands in the skin where hair follicles are. Amongst other things, sebum helps regulate the scalp’s microbiome, condition the hair and skin, and help them retain moisture. This is key to maintaining a healthy scalp. Depending on your genes, you may produce less sebum than is ideal for your scalp, making it more prone to dryness. In a similar vein, studies suggest that those who experience dandruff accompanied by scalp dryness also do so because of their genetic sensitivity to a particular free fatty acid - oleic acid. The oil-loving Malassezia fungus feeds off the oils on the scalp; oleic acid is a by-product of this process. This fatty acid is then free to breach the skin and compromise its barrier function, causing moisture loss from the scalp that leads to dehydration.

Nutritional & Hormonal Imbalances: Research continues to prove that we are indeed what we eat, and quelle surprise, it seems this is also the case with scalp dryness. A nutritional deficiency in iodine has been known to give rise to a hormonal imbalance in the thyroid, making it underactive. This condition is known as hypothyroidism, and whether it has been triggered by a nutritional imbalance or by an underlying disorder, one of its most common symptoms is dry hair and skin, which extends also to the scalp.

Reaction to medications: The use of certain medications can cause dry skin, especially when taken for an extended period of time. Common culprits include blood pressure medication, antihistamines, and cholesterol medication.

Age: As we age, our skin produces less and less sebum and gets drier as a result. This is especially the case for women who are going through hormonal changes - either due to the use of contraceptives or because of menopause. 

External/Environmental Causes.

Excessive Clarifying: Cleansing the scalp is important to maintaining a healthy scalp environment. However, the standard surfactants used in clarifying shampoos are designed to remove all dirt and oils from whichever surface it comes into contact with. This includes your body’s natural oils. Shampooing your hair and scalp too frequently (especially with a strong clarifying shampoo) can strip your scalp of its sebum and denature the proteins in your skin that help it retain moisture, leaving your scalp dry.

Hard water: Many water systems are treated with minerals like calcium and magnesium. These heavy metals can react with ingredients in your shampoos - and even in your sebum - leaving build-up on your scalp that can clog the pores and cause increased dryness over time.

Weather/Dry air: Your skin's (and scalp's) ability to retain moisture partially depends on the surrounding environment's humidity. The colder and drier the air outside, the quicker the moisture in your skin will evaporate. The skin is estimated to become up to 25% less effective at retaining moisture in colder seasons. This is often further aggravated by the use of forced hot air from indoor heating or the use of long hot water showers on wash days. Consistent blasting of hot dry hair and hot water on the scalp instead of cold dry hair can make it all the more irritated, itchy, and dry.

Treating and Preventing Scalp Dryness

In relation to the causes listed above, here are some appropriate, tried, and true remedies for combating dry scalp both internally and externally.

• Change your cleansing routine: In a bid to ensure your scalp remains clean and healthy, it is easy to overdo it. Though choosing how often to wash your hair will depend on your specific circumstances, a good place to start for curly-haired folk is once or twice a week with an effective co-wash or sulfate-free shampoo. Strictly co-washing is unlikely to cleanse the scalp adequately in the long run, but interchanging with a cleanser and introducing a clarifying shampoo every 4-5 washes will ensure the best balance. Good cleansers contain a combination of cleansing surfactants to remove scalp build-up of unwanted products, dirt, and excessive oils. They also contain fatty alcohols, oils, and conditioning surfactants to help replenish and support a good moisture level in the scalp. The Essential Moisture Cleanser is a prime example of such a cleanser, adding humectants like glycerin, which has been proven to improve scalp barrier function and keep the skin hydrated for longer.
• Mind your ingredients: In addition to glycerin, there are other ingredients that are backed by a ton of research and have been successfully used to treat and relieve dry scalps and skin. Allantoin works magic as a balancing act, regulating oily and dry scalps. As an emollient, it softens the scalp skin, soothing the itchiness that usually accompanies scalp dryness, and encourages skin cell regeneration. Hyaluronic acid is another humectant that is already present in the skin and helps it retain moisture. Over time, the skin can become depleted in this acid and, as a result, misses out on its superior moisture retention properties. You can find this in a lot of Curlsmith Scalp Recipes - including the Post Wash Calming Conditioner, Hydro Creme Soothing Mask, and the Weightless Air Dry Cream. Using scalp products that contain humectants and softeners like glycerin, allantoin, and hyaluronic acid go a really long way to help improve the scalp’s moisture retention abilities without the use of heavy oils that can throw off the scalp’s microbiome.
• Correct nutritional and/or hormonal imbalances: If your scalp dryness is a result of a nutritional deficiency or hormonal imbalance, the most important step to correct it will be to tackle the underlying cause. In the case of iodine and hypothyroidism, it may be worth speaking with your doctor about getting blood tests to confirm your levels, especially if your scalp dryness has also been accompanied by other common symptoms of the two conditions, like low energy, muscle aches, and/or weight gain.

Keep your scalp Healthy

Whether your concern is treating a flaky scalp, itchy scalp, or dry scalp, keep reading this scalp health series to discover the best tips to help you maintain a healthier scalp on all fronts, so you can not only achieve healthy hair growth, but also have a scalp that feels that way too!