Just as with every area of the skin, the scalp is prone to itching. This is particularly the case when it is oily. What are the reasons for this? Here is an overview of the causes of itching in an oily scalp and how to soothe it.
Oily scalp and itching: what is the connection?
An oily scalp is the result of a sebum overproduction by the sebaceous glands. This is a complex mixture of lipids that play a crucial role in protecting the scalp and skin in general. It acts as a barrier and contributes to the composition of the hydrolipidic film, whose role is to protect the scalp from external aggressions (dehydration, pollution, UV rays...).
Sebum also ensures thehydration of the hair. Indeed, once synthesised, it gradually flows along the hair fibres and coats them, thus ensuring their moisturisation. However, due to genetic predispositions, hormonal imbalances or external aggressions, it is not uncommon for the sebaceous glands to produce too much sebum, leading to a hyperseborrhoea.
Indeed, this accumulation of sebum on the scalp can lead to bacterial and parasitic colonisation, particularly by fungi Malassezia. These parasites, implicated in the onset of dandruff, have lipase activity, meaning they hydrolyse the sebum's triglycerides and release unsaturated fatty acids such as arachidonic acid. However, this subsequently produces prostaglandins, pro-inflammatory mediators responsible for scalp itching.
Furthermore, the fungi Malassezia and hyperseborrhea are associated with dandruff , which, when oily, clump together and stick to the scalp. They then block the pores and prevent sebum from flowing, which can lead to a local inflammation and a new release of prostaglandins. The scalp then becomes red, irritated and prone to itching.
Oily, itchy scalp: what to do?
Fortunately, there are several solutions to alleviate an itchy, oily scalp. This is generally achieved in two ways: easing the current itchiness and addressing the root of the problem, that is, targeting the hyperseborrhea to prevent its recurrence.
How to soothe scalp itchiness?
Some simple and natural actions can help to soothe an itchy scalp. You could first try toapply some cold, which has a calming effect. To do this, apply a cold compress or ice cubes wrapped in a clean cloth to your scalp for about ten minutes. However, be careful not to apply the ice cubes directly to your scalp. This could significantly irritate it.
In addition to the cold, the application of certain essential oils helps to reduce itching. Among the most reputedly calming essential oils and hydrosols, we find the tea tree essential oil, the true lavender essential oil and the Roman chamomile hydrosol.
How to reduce hyperseborrhea of the scalp?
To curb hyperseborrhea, it is initially advised against over-washing the scalp or using too much shampoo as it risks stripping the hydrolipidic film. Shampooing every other day is more than sufficient. Subsequently, you can try alternating between a "classic" product and a purifying treatment in order to reduce excess sebum and space out the shampoos.
You can also apply a clay mask to your scalp once a week. The absorbent and adsorbent properties of clay make it an excellent ingredient for mitigating hyperseborrhea. Finally, the use of certain essential oils with sebum-regulating action such as rosemary oil or citron oil can also be relevant.
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WIKRAMANAYAKE T. & al. Seborrheic dermatitis and dandruff: A comprehensive review. Journal of Clinical and Investigative Dermatology (2015).