What is keratosis pilaris?

Keratosis Pilaris, also known as KP, is a prevalent skin condition that causes rough bumps and redness (erythema) on the affected areas. It usually shows up on the upper arms, the thighs and buttocks, and can also affect the face.¹ It is a harmless condition that may cause slight discomfort and itching due to dry skin; therefore, individuals with KP usually seek treatment for cosmetic concerns. 

There is no cure for KP; however, management of the condition is possible.² There are a variety of treatment options that have traditionally helped with the appearance of KP-affected skin with consistent use. Recently, laser treatments have proven to be a highly effective alternative treatment option, as they deliver results without having to commit to frequent maintenance. 

This article will explore the available laser treatments for KP, their effectiveness and their risks. 

How is KP caused?

KP is caused by the excess keratin in the hair follicles, which results in a buildup and the appearance of inflamed bumps.¹ Keratin is the structural protein that is abundant in our hair, nails and outer layer of the skin. In KP, hair follicles get blocked by excess keratin and, as a result, form small, rough bumps.

It is uncertain why some individuals experience keratin buildup and develop KP. Some factors that may cause or contribute to KP are:

• Inheritance: KP is described as a hereditary condition with an autosomal dominant pattern of inheritance, meaning that if one parent has KP, their children have an estimated 50% chance of inheriting the condition³ 
• Vitamin Deficiencies: Vitamin A deficiency has been associated with KP⁴
• Dry skin and low humidity: lack of skin moisture tends to make KP worse, and as a result, colder months are usually when KP symptoms are more prevalent on the skin⁵
• Skin conditions: individuals with eczema or conditions causing dry skin are more prone to also have KP⁶

Traditional treatments

Management of KP can be achieved through several treatment options. While complete elimination of the condition cannot be achieved, consistent treatment has the potential to reduce the appearance of KP on the skin.

Keratin buildup can be reduced through chemical exfoliants, like AHAs (glycolic acid, lactic acid), BHAs (salicylic acid) and UREA-containing products. Retinoids that are applied directly to the affected area can also help with keratin accumulation, but may be too harsh for some individuals, resulting in irritation. If skin roughness and dryness are a concern, emollient-rich creams can moisturise the skin and help with issues of itchiness. Additionally, inflammation and redness may subside with the use of anti-inflammatory products, like niacinamide and topical corticosteroids.

Traditional treatments for keratosis pilaris may reduce the appearance of bumps and excess redness, but they only offer a temporary improvement to symptoms that often resurface after stopping consistent care.¹ In addition to that, skin sensitivity caused by KP is often exacerbated with the use of hard chemical exfoliants and active ingredients. For these reasons, laser treatments are being considered as an alternative option to treat the condition.⁷

Laser treatments for KP

Laser treatments deliver energy in the form of light to the area of choice in order to break down blockages or to promote cell growth and healing. Specifically for KP, laser treatments can target redness, pigmentation or texture of hair follicles- depending on the laser type. There are various laser treatments available for different skin concerns caused by Keratosis Pilaris. 

Before exploring the possible laser treatments for KP, it is important to understand how lasers work. Lasers are light beams emitted at wavelengths specific to their target. For Keratosis Pilaris laser methods, the target is usually haemoglobin and water, depending on the KP symptom that needs to be addressed. 

The following techniques are often categorised based on the type of laser treatment that they offer. Vascular lasers target haemoglobin and are primarily used to manage redness, while ablative or resurfacing lasers target water molecules and remove fractions of skin to promote healing. 

Targeting KP redness

Pulsed dye laser (PDL)

Pulsed Dye Laser therapy is a vascular laser technique with mild pain, suitable for all skin types. It targets superficial blood vessels responsible for redness associated with KP. The light used in this technique is strongly absorbed by haemoglobin, the molecule that fills our blood vessels and causes redness to appear on the skin. Once absorbed by haemoglobin, the laser beam heats the blood vessel and manages to shrink or break it down.⁸ However, it can cause bruising  (purpura) or temporary redness.

Targeting KP texture and pigmentation

Nd:YAG laser 

Neodymium-doped Yttrium Aluminium Garnet laser, or Nd:YAG, is a vascular laser technique. It targets deeper layers of the skin, reaching haemoglobin and melanin. Nd:YAG can heat up deeper blood vessels and destroy hair roots without damaging the surface, therefore directly reducing keratin buildup and redness associated with KP. ^9,10

Nd:YAG has minimal discomfort and is suitable for all skin types due to deeper penetration coupled with less melanin absorption, but it can leave bruising and temporary swelling.

Fractional CO₂  laser 

Fractional CO₂ laser therapy is an ablative or resurfacing laser technique. It is an effective method for KP bumps and thickened skin. This method is more superficial compared to Nd:YAG and focuses on the skin surface, which results in a longer recovery period. It targets the water molecules found in skin cells and acts by removing tiny fractions of the skin to stimulate healing and boost the production of collagen.¹¹ This therapy can cause mild to moderate pain, and burning sensation, as well as redness, skin peeling, crusting and may have a longer recovery time. It’s best for lighter skin types due to the risk of pigmentation changes (hypo- or hyper-pigmentation) and scarring in darker skin types.

Targeting KP bumps

Er:YAG laser 

Erbium-doped Yttrium Aluminium Garnet laser, also known as Er:YAG laser, is an ablative or resurfacing laser technique. It also targets water molecules that are found in the superficial layers of the skin. This method is able to remove surface layers of the skin with great precision, while also causing limited heat damage. By gently removing KP-affected skin, Er:YAG can sometimes reduce redness caused by the condition. For this reason, this method serves as a great combined approach to concerns regarding redness and KP bumps.¹² 

This technique can cause redness and swelling, and mild to moderate pain. It’s more gentle compared to fractional CO₂ lasers but requires more sessions and is suitable for all skin types, with caution due to increased chances of pigmentation changes for darker skin types. 

Effectiveness of laser treatments for KP

It is important to manage expectations when it comes to KP treatment options, as it is a condition that can only be improved or managed. Albeit more promising compared to traditional approaches, laser treatments often don’t provide a permanent solution. Nonetheless, laser therapy for KP-related concerns represents a great advancement in the management of the condition, offering noticeable improvements in erythema, pigmentation and texture. 

Treatment-specific research suggests: 

• PDL has shown a significant reduction in individuals targeting erythema ⁸ 
• Nd:YAG is particularly effective due to the deep skin penetration it offers, targeting erythema and keratin overproduction, while it is usually the preferred method for safety issues^10,13
• Fractional CO₂ laser treatment has shown a moderate to good level of improvement for pigmentation and skin texture concerns, but it is accompanied by a higher risk of pigmentation changes, especially for darker skin types. Additionally, a study comparing fractional CO₂ laser with a modulated, high-intensity type of Nd:YAG, called Q-switched Nd:YAG, found the two to be very safe and effective, encouraging their combination for an additive effect^11,14
• Er:YAG was compared to Q-switched Nd:YAG for pigmentation and skin texture issues, and proven as effective in targeting those concerns.¹⁵ While the pigmentation risk is elevated, especially for darker skin, Er:YAG is very precise and causes minimal heat damage, therefore decreasing the recovery period compared to ablative alternatives.

Risks of KP laser treatments 

Several risks come with laser therapy as a treatment approach for KP: 

• Darker skin types are more prone to post-inflammatory hyperpigmentation (PIH), while extra care is required for post-treatment management, compared to lighter skin types
• The slight discomfort experienced during the treatment, as well as post-treatment complications of erythema and swelling, may be discouraging for some individuals with sensitive skin
• Bruising may also occur, as well as slight peeling and scarring in rare cases¹⁶ 
• The laser equipment must be operated by qualified and experienced individuals, who will carefully evaluate the skin type, skin concerns and possible medical conditions of the patient 

Summary

Laser treatments for Keratosis Pilaris are a great advancement in managing skin concerns related to the condition, and a big step towards understanding KP on a deeper level. While traditional treatment options can improve the appearance of KP, the level of commitment they require, as well as their low success rate, may be discouraging. 

Laser treatments have proven significantly effective in reducing KP concerns, with longer-lasting results that require less frequent maintenance. Laser therapy alone, or combined with traditional treatment choices, can significantly help alleviate unwanted Keratosis Pilaris manifestations. Nevertheless, further advancements should be made for laser treatments that are available to all skin types.