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Why does an oily scalp itch?

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.

Summary
Published July 31, 2023, updated on January 27, 2024, by Pauline, Head of Scientific Communication — 4 min read

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 is part of 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 synthesized, it gradually flows along the hair fibers and coats them, thus ensuring their moisturization. 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 hyperseborrhea.

Indeed, this accumulation of sebum on the scalp can lead to bacterial and parasitic colonization, particularly by fungi Malassezia. These parasites, involved in the onset of dandruff, have lipase activity, meaning they hydrolyze 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 clog 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 done in two steps: soothe the current itching and address the root of the problem, that is, targeting the hyperseborrhea so it does not return.

  • How to soothe scalp itchiness?

    Some simple and natural actions can help soothe scalp itchiness. You can first try toapply 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 cold, the application of certain essential oils helps to reduce itching. Among the most reputed 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 scalp hyperseborrhea?

    To curb hyperseborrhea, it is initially advised not to wash your scalp excessively or use too much shampoo, as this risks stripping the hydrolipidic film. Shampooing every other day is more than sufficient. Next, you can try alternating between a "classic" product and a purifying treatment in order to reduce excess sebum and space out your shampooing sessions.

    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.

Sources

  • BEYLOT G. Les cheveux gras. Actualités pharmaceutiques (2013).

  • WIKRAMANAYAKE T. & al. Seborrheic dermatitis and dandruff: A comprehensive review. Journal of Clinical and Investigative Dermatology (2015).

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