Why Is My Scalp Itchy? Trichologist Explains It All
This one goes out to the itchy scalps, head patters, nail scratchers, and scalp massagers. Whether your preferred method is one or all of these, we’ve all been there at some point.
Itchy scalp, clinically known as ‘Pruritus’, refers to the (often irresistible) sensation that occurs as a result of irritation to peripheral sensory nerves.
Pruritus is more accurately identified as a symptom of conditions that affect the skin. A good number of scalp conditions list itching as a clinical feature, but at the same time, itching also occurs in all healthy scalps from time to time. In this blog post, we’ll cover some of the more common related conditions and causes for scalp itchiness, and also set out the best ways to keep your scalp healthy, and itch-free.
Common Causes of Itchy Scalp
Itchy scalp can occur either as a result of a condition localised to the skin itself or due to other internal conditions. When the itching is symptomatic of an internal medical condition, it will affect the entire scalp as opposed to just one area in particular. This is commonly the case with conditions such as diabetes, liver and/or kidney disease, iron deficiency anaemia, and thyroid imbalances, but it is quite rare.
Generally speaking, the most common scalp conditions when itching is present can usually be traced back to a reaction, an infestation, or an infection.
Scalp itchiness occurs frequently as a reaction to overly oily hair and/or dirty scalp. The scalp is constantly secreting a waxy-oil-like substance called sebum which, amongst other things, helps to regulate scalp pH, condition the hair and scalp, and keep the scalp from becoming dry. With every passing day, sebum mixes with everything from styling products, dirt from the environment and even your own sweat and dead skin cells. When left for long enough, this build-up on the scalp can clog the follicles, inflame the scalp and result in unpleasant itching that is usually relieved only when the scalp is cleansed.
How fast this build-up occurs will depend on a few things:
- natural sebum production speed on your scalp
- how much product you use in your hair (especially if those products are heavy),
- sweat levels
- whether you struggle with flaky scalp conditions.
Research has shown that people of African descent (who typically have curly or coily hair) tend to produce less sebum than those of European and/or Asian descent. This explains why itching from natural greasiness is less of a concern amongst this demographic. However, common practices in the textured hair community such as oiling the scalp often end up causing the very symptoms (e.g. itching) that the application of oil was intended to prevent or remedy.
The best practice to keep reactions under control is to be consistent in how often you wash your hair. The ideal schedule is to cleanse your scalp every 2-10 days. On the more frequent side of the scale will be those who naturally produce more sebum, and/or use heavy hair products or exercise often, and on the less frequent side will be those who do not.
Scalp Sensitivities & Allergies
It is worth noting that for people with sensitive skin, certain hair products can also cause allergic reactions that result in itchiness. The shift away from shampoos with sulphates occurred in large part for this very reason. Several detergents commonly used in shampoos have been proven to damage the proteins and lipids in the scalp, causing irritation and of course - itching. However, even “milder” sulphate-free detergents can be just as irritating to sensitive skin. So if you’re someone who has a sensitive scalp, be mindful as you choose a co-wash or a shampoo to use. Co-washes like the Curlsmith Curl Quenching Conditioning Wash are great options for gentle but effective regular cleansing in between major clarifying sessions. When clarifying, you can opt for a more thorough cleanser like the Wash & Scrub Detox Pro-Biotic which can help rid your scalp of unwanted build-up - without the use of harsh surfactants that may aggravate irritation and itching.
Poor hair care practices can encourage the growth of unwanted bacteria on the scalp. The development of such bacteria can often result in infections that cause itching. Itching and scratching in these affected areas can become so severe that it creates open wounds on the scalp, which lead to secondary infections. Talk about a catch 22!
Such infections are usually treated with broad-spectrum antibiotics as prescribed by a doctor. Nonetheless, there remain a few easy adjustments you can make to your regimen that can help prevent you from ever getting to that point.
- Get on a regular hair & scalp cleansing routine. Sporadic cleansing leaves room for unwanted bacteria to grow and multiply.
- Avoid the use of improperly formulated DIY concoctions, specifically those that have been made without preservatives and have been left to sit for days.
- Avoid the application of heavy/oily products onto the scalp. Many unwanted bacteria that grow on the scalp are lipid feeding. By adding more oils to your scalp than it already produces/needs, you run the risk of feeding the bacteria you’re trying to avoid.
The title of this subsection sounds like the name of a bad horror movie, and if you have experienced this condition yourself, you’ll know the reality isn’t too far removed. Pediculosis Capitis, more commonly known as lice, is a very well known and extremely contagious condition that causes severe itching.
Itching is usually localised to the occipital (back) area before spreading to other parts of the scalp. Lice position themselves on the hair close to the skin because they feed off our blood to survive. Their preference for the occipital part of the scalp is also no coincidence, as that highly vascular area hosts the notable Occipital Artery that supplies a lot of blood to the scalp as well as your neck and back muscles.
Once lice reach maturity (typically within 10 days of being laid), they can each lay up to 10 more eggs per day, all of which will go on to have an adult lifespan of roughly a month. It’s probably best not to do the math, but safe to say…that’s a lot of lice. As they feed off the blood, it is their saliva that causes irritation and itching. The severity of the itching is then determined by the sensitivity of the host’s scalp to the louse’s saliva.
For those who are experiencing ongoing itching in this area, it is always best to check for lice, and get rid of them immediately should they be found. This is typically done with shampoos and treatments specially formulated to kill off both lice and nits, and is followed by removing them with a fine-toothed comb. This second part can be tricky for those of us with curly and tightly coily textured hair, so it always helps to have a super slippery conditioner handy and work in small sections to comb out all unwanted guests.
5 Signs It’s Time to See A Professional
With all this in mind, it can still be difficult to know whether the scalp itch you’re experiencing is normal, or if it is symptomatic of an underlying condition. You should make an appointment with a local trichologist or dermatologist if the itching:
- Persists for over a few weeks
- Comes with burning, red flaky patches, white scaling, or pus-filled pimples
- Is so intense that you scratch it to the point of bleeding.
- Causes or is accompanied by hair loss in the inflamed area.
- Takes place at the bottom/back area of the head and is severe.