Itchy keratosis pilaris: what are the reasons?

Keratosis pilaris is caused by an overproduction of keratin by the keratinocytes, leading to its accumulation in the hair follicles. Keratin is a protein that ensures skin protection. It forms the basic element of nails and hair, in addition to maintaining the skin's barrier function. However, when it is synthesised in excess, keratin can cause the appearance of small follicular plugs and give the skin a "strawberry skin" appearance. Keratosis pilaris usually results from a genetic predisposition , with an anomaly on the FLG gene coding for filaggrin, the protein associated with keratin in the epidermis and playing an essential role for the integrity of the horny layer.

The symptoms associated with keratosis pilaris most commonly appear on the arms and calves but can also extend to the thighs, buttocks and, less frequently, the neck or face. This benign condition is extremely common and affects approximately 40% of adults worldwide. Difficult to treat, the discomfort caused by keratosis pilaris is often purely aesthetic. However, it can sometimes be accompanied by itching, ranging from mild to moderate in intensity.

The accumulation of keratin in hair follicles, a characteristic of keratosis pilaris, creates a environment conducive to irritation and inflammation. Indeed, this obstruction disrupts the natural hair growth process and can prevent its normal emergence through the skin's surface. However, when hairs are blocked in this way, they may not grow properly and bend, thus forming ingrown hairs, exacerbating inflammatory phenomena and sensations of tingling and burning.

From a biological perspective, inflammation is characterised by the release of chemical mediators of inflammation such as cytokines. Interleukin-1 (IL-1) and tumour necrosis factor (TNF-α) are cytokines secreted by immune cells in response to inflammation. They play a key role in the recruitment and activation of other immune cells and constitute a first line of defence against pathogens. Prostaglandins can also be mentioned, which are metabolites of arachidonic acid contributing to the process of vasodilation, pain sensation and itching.

In the case of keratosis pilaris, the itching is temporary, the irritation associated with the presence of ingrown hairs can be easily soothed.

Fortunately, there are several tricks to soothe the itching associated with keratosis pilaris.

• Hydrating one's skin.

  Hydration is the ally of skin diseases. In the case of keratosis pilaris, it helps tosoften the skin and to reduce its roughness , while aiding in the reduction of irritation and, consequently, itching. To hydrate the skin, it is recommended to apply an emollient treatment like our relipidating balm several times a day, in a thin layer. It is also possible to resort to thermal waters, rich in minerals and trace elements with soothing virtues. This can be achieved by performing prolonged sprays or applying compresses soaked in cool water directly onto the skin.

  Tip : to enhance the effectiveness of your moisturising treatments, you can add a few drops of true lavender essential oil, peppermint essential oil, or even Roman chamomile hydrosol, natural ingredients renowned for their anti-inflammatory and soothing properties.

• Applying cold.

  Cold is also highly recommended for numbing itchiness. It indeed has a vasoconstrictive action, meaning it causes a narrowing of the blood vessels and can reduce the skin inflammation associated with itching. To benefit from its effects, apply a cold compress, previously placed in the refrigerator, to the itching areas for about thirty minutes. You can also use ice cubes, provided they are wrapped in a clean cloth. Indeed, it is important to not apply ice cubes directly onto bare skin, as this risks causing a burn.

• KHOPKAR U. S. & THOMAS M. Revisiting Keratosis Pilaris: Is It More Than Just a Follicular Keratosis? International Journal of Trichology (2012).

• WANG J. F. & ORLOW S. J. Keratosis Pilaris and its Subtypes: Associations, New Molecular and Pharmacologic Etiologies, and Therapeutic Options. American Journal of Clinical Dermatology (2018).

• FELDMAN S. R. & al. Treatment of keratosis pilaris and its variants: a systematic review. Journal of Dermatological Treatment (2022).