Keratosis pilaris: what you need to know about this skin condition.

The keratosis pilaris is a benign cutaneous disorder. The symptoms of keratosis pilaris are easily identifiable. It is characterized by small flesh-colored papules that it produces, sometimes surrounded by a pink or brown halo. These lesions may also appear as white bumps on the arms, small red bumps on the legs, or bumps on the thighs. Although these imperfections can occur on various body sites, they typically manifest on the outer aspects of the arms, thighs, and calves. In these regions, the skin is dry, rough in texture, and exhibits an irregular surface, which many perceive as numerous tiny itchy bumps on the arms or as dryness-related bumps.

Keratosis pilaris generally disappears spontaneously in one’s twenties. However, in some cases it persists over time and can be a source of discomfort and self-consciousness, especially in summer when the weather invites you to expose your legs and arms. Furthermore, although benign, the keratosis pilaris sometimes causes itching. If inflammation follows scratching, the tiny follicular plugs may turn red. In certain cases, the keratosis pilaris leads to an increase in ingrown hairs. It should also be noted that it can affect very young children. Keratosis pilaris in babies is often mistaken for other types of small bumps on the body

Keratosis pilaris results from a dysregulation of the keratinization process, more precisely an excessive production of keratin by keratinocytes. Trapped in the hair follicles, the excess keratin accumulates, eventually blocking them. Several studies have been conducted to understand the origin of keratosis pilaris and scientists have eventually demonstrated the hereditary nature of this condition. It is transmitted in an autosomal dominant pattern, meaning the mutation occurs on a non-sex chromosome and only one copy of the gene needs to be affected. A mutation in the FLG gene is thought to be involved. This gene encodes filaggrin, a protein that associates with keratin in the epidermis and contributes to its barrier function.

Beyond this well-documented genetic component, several additional factors are suspected to contribute to the development of keratosis pilaris. Some hormonal variations, notably during adolescence, pregnancy or certain phases of the menstrual cycle, could influence keratinization and promote the formation of the characteristic keratin plugs of keratosis pilaris. Some research teams also suggest a possible link with insulin resistance: excess circulating insulin may disrupt keratinocyte differentiation, though this mechanism remains theoretical.

Similarly, an unbalanced diet, low in fatty acids or vitamins involved in barrier function, could promote follicular blockage. It should be noted that these are only hypotheses and that further research is still needed to draw a definitive conclusion.

Finally, people affected by atopic dermatitis or ichthyosis appear particularly predisposed to developing keratosis pilaris. These conditions indeed share common pathophysiological mechanisms, notably impaired skin barrier function, pronounced dryness, and abnormal keratinization, which together create a favorable environment for follicular plug formation.

To alleviate the symptoms of keratosis pilaris, it is useful to adopt a tailored skincare routine.

• Regular and gentle cleansing of the skin.

  While cleansing the skin is essential, it is important to use gentle products that do not damage the skin barrier, which is already compromised in cases of keratosis pilaris. To achieve this, we recommend choosing a mild, hydrating cleansing care product such as a dermatological cleansing bar. Formulated at the skin’s physiological pH, this type of care helps maintain the hydration of the stratum corneum and is suitable for all skin types, including the most sensitive.

• Perform exfoliation once or twice per week.

  All skin types benefit from the application of an exfoliating treatment once or twice a week, those affected by keratosis pilaris have an even greater need. Indeed, these products allow you to remove dead cells that have accumulated on the skin’s surface, thereby helping to unclog hair follicles. Additionally, exfoliating treatments help soften the epidermis and combat the roughness caused by keratosis pilaris.

• Daily hydration.

  Moisturizing your skin daily isn't just for people with dry skin. In addition to protecting the epidermis from external aggressors and limiting water loss, the application of emollients helps to soften the skin and reduce roughness. These properties are particularly beneficial for keratosis pilaris. Alongside a moisturizing cream or balm, the application of vegetable oils and butters, such as argan oil and mango butter, are also beneficial.

• Avoid handling keratin plugs.

  While it can sometimes be tempting, it is strongly recommended not to scratch, pierce, or attempt to extract the small keratin plugs caused by keratosis pilaris. This could compromise the skin barrier and trigger micro-inflammations and redness. Additionally, depending on your skin phototype, there is a risk of hyperpigmentation or post-inflammatory erythema. To remove keratin plugs, it is best to rely on exfoliating treatments.

It is not necessary to treat keratosis pilaris because it is harmless to your health. Of course, you can always remove it for cosmetic reasons.

It is important to note that most treatments aim to alleviate the symptoms of keratosis pilaris, without completely eliminating them. Among the active compounds studied in scientific research for their keratolytic properties, one can notably cite the retinoids, such as tretinoin and adapalene, the azelaic acid and calcipotriol, a vitamin D derivative. Topical application of creams containing these ingredients helps improve the appearance of keratosis pilaris but does not eliminate it.

A more effective solution for treating keratosis pilaris is laser therapy. However, note that this technique is not suitable for pregnant women or for individuals undergoing photosensitizing treatment. Several aesthetic centers offer laser sessions aimed at eliminating keratosis pilaris. The type of laser used in these centers varies: it may be an Nd:YAG laser, a CO2 laser, or a pulsed-light laser. These different lasers have comparable efficacy against keratosis pilaris. Although the results after multiple laser sessions are often satisfactory, they are unfortunately temporary. Indeed, when the sessions are discontinued, a relapse is generally observed.

Several studies have assessed the efficacy of laser treatment in reducing keratosis pilaris. A very recent trial examined the effects of the 755 nm alexandrite laser compared with simple daily moisturization. Twenty-one participants underwent four laser sessions on one arm at three-week intervals. Four weeks after the final session, both physician and patient assessments showed a clear improvement on the treated side, with a significant decrease in skin roughness and redness. Complementary evaluations (dermoscopy, high-frequency ultrasound, and biopsies) confirmed these results, with a more pronounced reduction of keratin plugs on the laser-treated side. However, three cases of post-inflammatory hyperpigmentation—fortunately reversible—were observed.

Overall, the study concludes that the 755 nm alexandrite laser is an effective option for mitigating the characteristic roughness and redness of keratosis pilaris.

Hair removal and keratosis pilaris do not always mix well, and a poor technique can quickly lead to the development of ingrown hairs. To prevent them, we recommend avoiding electric epilators and wax. Although these removal methods are convenient and popular for extending the interval between sessions, they promote ingrown hairs by extracting hair directly from the bulb. Sometimes, obstructed by excess keratin, the hair fails to grow straight, instead curling within the epidermis and becoming embedded. This triggers inflammation and a small red bump, similar to those caused by keratosis pilaris.

In cases of keratosis pilaris, it is generally recommended to use depilatory cream or laser hair removal.

The depilatory cream and laser are more strongly recommended for individuals with keratosis pilaris. Indeed, the former neither alters the hair bulb nor affects hair growth. Depilatory cream works by targeting keratin and softening hairs, which shed after a few minutes. The laser, effective in the long term, operates on the principle of selective photothermolysis: the infrared beams it emits are absorbed by the melanin in the hair and convert to heat to destroy the entire follicle. Although suitable for all skin phototypes, the laser hair removal is, however, not feasible for very light-colored hairs, during pregnancy, or when taking photosensitizing medications.

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