Keratosis Pilaris (Chicken Skin on the Arms): Causes and What Helps

The essence of KP is follicular hyperkeratosis: keratinocytes around the opening of the hair follicle stick together too tightly and in too great numbers, forming a keratin plug that closes the opening and often coils the hair inside the follicle. The result is a rough bump, easier to feel than to see. A small area of redness may appear around the bump because the plug triggers mild inflammation. This is a retention mechanism, not an infectious one: there are no bacteria or dirt involved, and 'squeezing out' the plugs usually makes things worse.

Several practical conclusions follow. First, KP has a genetic and barrier component: in some people it is linked to mutations in filaggrin (a protein of the epidermal barrier) and clinically coexists with dry skin, ichthyosis vulgaris and atopy, although the review by Kodali et al. (2023) notes that the link with atopic dermatitis is less certain than with ichthyosis. Second, there is no 'single explanation': filaggrin mutations were present in only 35% of patients in the study described. Third, because the cause lies in the skin itself and not in diet or 'toxins', no supplement or body cleanse treats KP in an otherwise healthy person.

Diagnosis is clinical, that is, based on the appearance and location of the lesions: small, uniform, follicle-centred bumps, rough to the touch, often clustered on the extensor sides of the arms and thighs. In some people redness dominates, and this is called the red variant (keratosis pilaris rubra); scarring variants on the face are rarer. The changes usually worsen in winter when the air is dry and improve in summer, which fits with a role for dry skin, although study evidence is scant.

The differential includes folliculitis (bumps with pustules, often painful or itchy, after shaving), lichen spinulosus, ingrown hairs after hair removal, trichostasis spinulosa and, rarely, phrynoderma, follicular hyperkeratosis in severe malnutrition linked to vitamin deficiencies. In a healthy, well-nourished person with typical changes on the arms since youth, further testing is therefore usually unnecessary. It is worth showing the changes to a doctor, however, when they are atypical, painful, scarring, rapidly worsening or affecting the face and eyebrows.

A more recent systematic review by Beyron (Eur J Dermatol, 2025), covering 27 articles from 2011–2024, indicates that the preferred topical agents were lactic and glycolic acids, which showed efficacy, and that the Nd:YAG laser gave consistently favourable results. Among ablative lasers the CO2 laser was effective, while the erbium:YAG appeared promising because of fewer adverse effects. The author notes, however, that no standardised way exists to choose one treatment over another, and proposes a stepwise, multimodal approach: patient education, topical treatment and lasers.

The review by Suástegui-Rodríguez et al. (Skinmed, 2022) reaches a similar conclusion more cautiously: lactic acid, salicylic acid and the 1064-nm Nd:YAG laser seem to be the most effective and safe options for people aged 12 and older, but high-quality randomised trials with long follow-up are needed. A 2025 review by Dampa on keratolytics (AHAs, BHAs and urea), in turn, considers them a reasonable first-line treatment while noting that the evidence base is limited by small samples, varied outcome measures, weak blinding and short follow-up, and that data on maintaining the effect are lacking.

Keratolytics loosen the bonds between horny cells and promote shedding, so they act on exactly the mechanism of KP. The review by Kodali et al. (2023) names topical keratolytics as first-line therapy and topical retinoids and corticosteroids as the next steps if the first treatment is not enough. Over-the-counter products usually contain urea (in concentrations from a few to over ten percent), lactic acid, glycolic acid or salicylic acid; the higher the concentration, the greater the risk of irritation.

Practical advice that follows from reviews and clinical experience is as follows. Use the product regularly, usually once or twice a day, on the whole area affected rather than on single bumps, because the effect builds over weeks, not days. Start with a lower concentration and increase if the skin tolerates it. Combine the keratolytic with a moisturiser, because dry skin worsens KP. Avoid applying acids to damaged or irritated skin and do not combine several strong acids at once. Salicylic acid in large amounts over wide areas is not recommended in children or in pregnancy without a doctor's advice.

An honest correction of expectations is also important. Studies assessed improvement in smoothness and appearance, not complete disappearance of the lesions, and data on how long the effect lasts after stopping are lacking. Many people therefore treat a keratolytic as ongoing care, like a moisturiser, and not as a course after which the problem vanishes for good. When the skin is clearly red, a doctor may consider brief anti-inflammatory treatment and, in resistant cases, topical retinoids.

The systematic review by Kechichian et al. (Dermatol Surg, 2020), covering 17 studies and 175 treated people, considers lasers and light a promising option in a condition that still lacks an effective long-term treatment. The review by Wong et al. (Clin Exp Dermatol, 2024) indicates that lasers and light have the most developed evidence base, with the Nd:YAG laser as the preferred option with a relatively favourable side-effect profile, but stresses inconsistent outcome measures and the need for a standardised KP scoring scale.

It is similarly wise to be cautious about cosmetics promising 'complete removal' of KP. Reviews describe improvement, not disappearance of the lesions, and studies on individual products are small and often unblinded. The best approach is to set a realistic goal: smoother and less red skin, not a perfectly uniform texture. We are also cautious about invasive procedures such as microneedling or strong chemical peels, for which solid data in KP are lacking.

Keratosis pilaris is one of those complaints in which setting expectations matters most. It is not a disease or a defect but a chronic trait of the skin that can be softened with regular moisturising and keratolytics and, in justified cases, with a laser. It is not worth giving up summer in short sleeves because of changes that are not dangerous, nor investing in expensive, unproven regimens in the hope of perfect skin.