Hyaluronic Acid for Acne: Hype or Help?

Acne is caused by an alteration within the skin's pilosebaceous follicle where dead cells, oil (sebum) and particles build up and clog it, causing inflammation.

It is well known that it is a long-lasting and relapsing dermatological condition that produces painful pustular lesions, often known as pimples, which give the skin an uneven complexion and a reddish appearance.

However, although it seems to involve only the skin, acne goes beyond blackheads and pimples, hence its nowadays attention. The face skin has always been a synonym of self-presentation. The first thing everyone sees when they meet you is your face, and how it looks is always the first impression.

For many, having acne decodes into a self-esteem problem that makes life difficult, even if the lesions do not compromise any vital function. There are a variety of effective treatments for it, but it can be challenging to treat from mild to most severe forms.

Among the many skin products used today is hyaluronic acid, an ingredient that promises to redefine the face lines, improve texture, induce cell repair, diminish wrinkles and fill in furrows. But is a daily serum capable of fulfilling all these functions and improving acne? Let's find out. But first, let's look at what acne is all about.

Pathogenesis of acne vulgaris

The pimple in acne results from a sequence of different processes within the pilosebaceous unit¹:

Increased sebum production by overactive sebaceous glands.
Hyperkeratinisation: cells become cohesive and do not normally shed onto the skin's surface.
Bacterial overgrowth supported by the above circumstances.
Inflammation that ends in a painful swollen pimple.

All four aspects tend to arise during the pubertal transition when changes in the body's hormonal milieu alter pilosebaceous gland function.

When the androgens storm appears, the epithelial cells of the skin form tighter adhesions between them and are therefore less easily shed. This process leads to hyperkeratotic plugs, or the known microcomedones, which progressively enlarge to non-inflammatory, closed or open comedones.² Androgens also increase sebum production, further increasing facial oiliness, contributing to more comedones.³

Cutibacterium acnes (C. acnes), a typical bacterium of the cutaneous flora, inhabits the pilosebaceous unit using lipid-rich sebum as a nutrient source, the reason why the more sebum there is, the more bacteria grow and the more inflammation.² ⁴

The distribution of acne lesions depends on pilosebaceous gland density and size. Thus, it is common where these structures are most prominent and abundant, such as the face, chest, neck, and back.

Depending on whether inflammation is present or not, there are broadly two types of acne:

Non-inflammatory acne: Includes non-inflamed lesions such as open or closed comedones and microcomedones (popularly known as blackheads).

Open comedones, or blackheads, demonstrate darkly coloured hyperkeratotic plugs within the follicular opening. This dark colouration is related to the oxidation of melanin and not dirt, as many mistakenly think. Closed comedones, or whiteheads, are white to flesh-toned in colour and seem not to have a central open pore.

Inflammatory acne: Inflammatory acne vulgaris lesions develop when comedones rupture and contents of the pilosebaceous unit spill into the surrounding dermis, causing inflammation. This kind of acne is the one that causes blemishes or scars after the lesions have disappeared.

Many problems can increase hormones, such as endocrine tumours and polycystic ovary syndrome. Even genetics can cause you to have acne.⁵

Acne treatments

Many products promise to cure acne or play a role in it nowadays, especially on social media. However, the actual acne treatment is focused on addressing the critical steps in its development according to recommendations made by dermatologists worldwide.

Among the expert societies leading the way in acne treatment is the European Academy of Dermatology and Venereology⁶, which claims that products to be used depends on the severity.

Among the highly recommended ingredients are antibiotics such as clindamycin, retinoids such as isotretinoin, benzoyl peroxide and azelaic acid, which are used in combination for most forms of acne. Rarely a single ingredient is used.

These active ingredients are intended to stop each step of acne, and most are multi-purpose, such as retinoids that target inflammation, sebum production and decrease the skin load of C. acnes.⁷

Although not listed among the main medications, other active ingredients help acne to some extent, either by enhancing the effects of the previous ones or by reducing the side effects. Such is the case with salicylic acid⁸, which has comparable action to azelaic acid, or glycolic acid⁹, which provides a chemical peeling that improves the skin's texture and normalises the keratinisation process.

However, these are considered cosmeceuticals and not pharmaceuticals, which are topical products sold as cosmetics but with performance features that suggest pharmaceutical action, affecting the skin positively beyond the time of its application.¹⁰

It is essential to keep this concept in mind because most of the products sold today are cosmeceuticals under the premise that they cure acne, when they do not.

In fact, dermatologists around the world rarely recommend cosmeceuticals to treat acne. If they do, it is to improve other symptoms or supplement the skincare routine, not as a treatment.⁶

Hyaluronic acid and its role in acne

Hyaluronic acid (HA) is a naturally occurring linear polysaccharide composed of glucuronic acid and N-acetylglucosamine.¹¹ It is in all body tissues and is the same throughout the body. It is also biocompatible once administered in humans.

HA is the central substance in the synovial fluid of joints, acting as a lubricant for the cartilage and regulating the viscosity of the synovial fluid. ¹¹ It is also in the eye's vitreous fluid, umbilical cords, and chicken combs.¹²

It is a highly viscoelastic fluid capable of reproducing and repairing the rheological properties of synovial fluid. In addition, it has anti-angiogenic, anti-inflammatory and analgesic properties, as well as immunosuppressive capabilities.¹²

By a passive mechanism, high molecular weight HA permits the tissue hydration, contributes to the osmotic balance, and stabilises the extracellular matrix structure¹³. However, many of its effects have been tested under strict aseptic conditions in medical settings, such as fillers¹⁴, injected gels¹⁵, and non-cross-linked with dermapen, but none in daily topical cosmetics.¹⁶

It should be noted that several hyaluronic acid molecules works depending on their weight: high molecular weight, medium molecular weight and low molecular weight. The first is mainly for hydration and remains on the epidermis surface. The latter penetrates the epidermis and prevents water loss. The third, the smaller one, is the key in wounds, scars, and collagen production because it reaches the dermis and promotes skin repair.¹³

This is where the problem arises. Most cosmetic products do not specify what type of HA molecule they contain, and most only have high molecular weight HA, so they would only provide hydration.

To date, no scientific evidence confirms that daily application of a serum containing hyaluronic acid benefits acne, although its injected use for the recovery of the acne atrophic scars continues to be studied and recommended.¹⁶ ¹⁷

Following the inflammation associated with acne, the subsequent scarring is attributed to an interplay of several mechanisms, including inflammation, granulation tissue formation and matrix remodelling. Treatments used by dermatologists for acne scarring include chemical peels, dermabrasion, ablative and nonablative laser devices, punch excision, dermal grafting, fillers and fat transplantation, but this is already out of our point.¹⁶

Hyaluronic acid as a moisturiser in acne

Moisturisers are emollients composed primarily of occlusives, lubricants, and humectants. Humectants promote moisture retention and are always recommended to support a healthy skin barrier.¹⁸

In cosmetic formulations, HA is a viscosity modifier and/or a skin conditioning agent that can enhance the skin's level of moisture and expedite regeneration. It also reduces water evaporation from the skin because it can bind water up to 1000 times its volume and thus possesses an occlusive effect.¹²

Due to its potential moisturising function, hyaluronic acid serums should be recommended for dry, non-acne-prone skin. It could be used as a cosmeceutical in acne patients undergoing treatment with ingredients that drastically decrease sebum production and dry out the skin, such as retinoids. Otherwise, it has no effect on acne-prone skin when used in cosmetic serum.

Conclusion

More is being learned about hyaluronic acid every day. It is undoubtedly beneficial for the skin and many of its conditions, but there is a fine line between true benefit and hype.

Hyaluronic acid is undoubtedly an active ingredient with powerful moisturising properties, ideal for dehydrated skin, but it makes little difference in acne. In fact, if misused or mixed with other ingredients without medical supervision, it could make pimples worse because it may contribute to pore-clogging.

As is well known, acne is a challenging disease for both the physician and the patient. Many patients give up treatment because they do not see immediate results, while others do so because they cannot tolerate the side effects. As a cosmeceutical, hyaluronic acid can help improve the dryness caused by the treatment to ensure that patients do not forgo treatment.

However, whether or not to use a hyaluronic acid serum is up to your dermatologist rather than you, especially if you suffer from severe acne with inflamed and painful lesions.