It starts with the scalp

Having a dry spell? We get to the roots of the causes of a thirsty scalp and what you can do about it. 

For strong hair at optimum health, you need to have a happy scalp. Whilst previously it could be considered as the ‘Cinderella’ of the anatomy, the scalp is well and truly having its time in the spotlight with scalp products and routines trending as we begin to realise what the trichologists have been trying to tell us all along – good hair begins at the roots.  

But what if your hair doesn’t feel strong and resilient? You may have a problem that begins with the scalp and particularly the hair follicles. Scalp problems are often felt as much as seen and if you have been suffering with dryness, flakiness, itching and irritation, chances are you have an excess or lack of scalp oil. 

There are many reasons why your scalp may become dry, including something as simple and reversable as over-washing. Shampooing daily can be necessary but if care is not taken (i.e you double cleanse too much, or use too hot water), it can strip your scalp of essential natural oils. Continuing over time, this can lead to hair breaking. So, what is a healthy number of times to wash your hair per week? This is down to your hair type. Those with fine locks may find they need to shampoo daily, whilst those with coarse hair might not need to wash their hair as frequently. As well as taking note of how your hair feels after a day of not shampooing, we also recommend checking with your hairdresser if you are unsure.  

Another cause of dry scalp can be Contact Dermatitis. ‘Contact dermatitis on the scalp will often result in itching and is caused by a reaction to the chemicals in some shampoos, hair dyes or other grooming products’ explains Deborah Whelan Hair@TheSkinNerds resident trichologist. ‘It may be that the person has an allergic reaction to certain ingredients that are in the product or that the ingredients simply irritate the skin. This condition will be recognised by your Trichologist and can be treated if necessary.’ The best remedy is to strip back your regime until you discover which product caused the reaction and remove the culprit pronto

Changes in the temperature can also be a cause of a thirsty scalp. During the winter, the humidity in the air drops and this can cause the skin across the whole body to become drier. The techniques and tools you use to wash and style your hair can also make a difference. Using a too hot setting on your hairdryer or scoldingly hot water in the shower can lead to irritation and dryness. To avoid this, stick to warm water when bathing and consider getting a humidifier to add moisture to the air in your home.  


Skin conditions such as eczema and psoriasis can also affect the scalp too. Eczema is an inflammatory skin condition that can also affect the skin on your scalp, leaving it red, dry and itchy.** Types of soap, shampoos, cleansing products and intrinsic factors such as stress can lead to a flare up of symptoms and cause patches of eczema to develop on many places across your body including the scalp. It is important to identify and avoid harsh shampoos or any other products or ingredients that trigger your symptoms, such as cocamidopropyl betaine, which is used to thicken shampoos and lotions and has been identified by The National Eczema Organisation as a common trigger.** Psoriasis is said to affect 1 to 2% of the general population and can affect any part of the body. According to the National Psoriasis Foundation, as many as 45% to 56% of those with psoriasis have it on their scalp. When it comes to psoriasis, your autoimmune condition causes your skin cells to multiply faster than usual. The additional cells build up on the skin and create plaques (itchy, scaly patches) which can occur on your scalp. As psoriasis is a medical condition, your first port of call would be to discuss this with your GP or trichologist but for mild scalp psoriasis, they are likely to suggest trying a medicated shampoo that contains juniper tar, rosemary or thyme oil which can help to relieve the itch.  


Ask our expert: Does your shampoo really make a difference? 

‘Yes!’ says our in-house trichologist, Deborah Whelan. ‘It is important to seek professional advice on which shampoo you should use regularly as shampoos are tailored to individual hair types. The pH of hair naturally lives between 4.5-5, which is in the acidic level. The natural oil secreted from the scalp is responsible for the pH of our hair. Scalp oil is naturally more acidic as this is helpful at fighting off bacteria and the growth of fungus. When we use a hair product such as a shampoo that has a pH of 7 or higher, that high alkalinity can cause irritation to the scalp and can leave the hair feeling dry. The pH scale ranges from 0 to 14 pH. Any liquid that is between zero and 6.99 pH is acidic. Any liquids that are between 7.01 and 14 pH are basic, or alkaline. Water itself has a pH of seven, which is considered to be neutral since it is equal parts acids and alkalis. Most shampoos are between 3.5 to 9 on the pH scale, which is a wide range. If you are using a shampoo that is too high or too low on the pH scale, then you might be interfering with your scalp’s natural pH balance, causing hair damage and scalp irritation. When you use a shampoo with a very high pH, your scalp and hair will feel very clean, and your hair may appear fuller but after time your hair will become dry and dull from a lack of oil. Shampoos with a very high pH will begin to lift the follicle’s outermost layer (known as the cuticle). This is what gradually leads to split ends, frizz, and breakage over time. A very acidic shampoo can also cause scalp irritation, so to maintain healthy looking hair and avoid drying out the scalp the pH of shampoos should be less than 7. My recommendation for a shampoo would be one with a pH of around 5 -5.5.’ 

Always book an appointment to see your GP or trichologist if your scalp is red, swollen, painful or warm to touch, if you develop a rash or if the itchiness of your scalp is severe and unexplained. 



* Saxena R, Mittal P, Clavaud C, et al. Comparison of Healthy and Dandruff Scalp Microbiome Reveals the Role of Commensals in Scalp Health. Front Cell Infect Microbiol. 2018;8:346. doi:10.3389/fcimb.2018.00346 

** Eczema (atopic dermatitis): Causes, symptoms, and treatment (