Subclinical Acne: What Is It & How Can You Treat It?

If you suffer from acne you are far from alone. In fact, the majority of people will experience acne breakouts at some point during their lifetime. You’ve probably heard of inflammatory and non-inflammatory acne, but what about subclinical acne? What the heck is that? Is it even a thing or is it just another trendy skincare term floating around the internet?

What Is Subclinical Acne?

If a health condition is classed as ‘subclinical’, it means that it does not yet have any visible symptoms. Subclinical acne is, therefore, acne without any visible whiteheads, blackheads, papules, pustules, nodules, or cysts. However, it isn’t a true medical term and, as such, is often misinterpreted.

In order to understand this better, here is a quick recap of how acne forms:

• Hormones cause the oil glands within the pore to overproduce oil.
• A build-up of dead skin cells on the surface of the skin blocks the pore and prevents the oil from escaping.
• Bacteria that are naturally present in the pore (p.acnes/c.acnes) feeds off of this oil and rapidly multiplies.
• The body senses this increase in bacteria which leads to an immune response and inflammation.

The blocked pore, officially called a ‘comedone’, is usually the point where acne becomes visible. If the blockage causes the pore to stretch open, the blockage itself oxidizes and turns a brownish/black color. This type of acne lesion is called an ‘open-comedone’, on account of the fact that it is exposed to air, but is better known as a ‘blackhead’.

If the blockage does not stretch the pore, the pore remains closed but causes a small bump on the skin. This type of acne lesion is called a ‘closed-comedone’ but is better known as a ‘whitehead’ and is responsible for those pesky forehead bumps.

Both blackheads and whiteheads are classed as non-inflammatory acne, the latter of which may sometimes be referred to as ‘subclinical acne’. However, whiteheads count as a ‘clinical presentation’ of acne as these bumps are visible to the naked eye.

Actual subclinical acne is a little more complicated.

In the medical literature, subclinical acne is better known as ‘microcomedones’ which are described as ‘the clinically non-visible central precursor lesions of acne’ ^[1] or ‘specialized skin compartments where acne arises’ ^[2]. In other words, subclinical acne is what leads up to the blocked pore and resulting acne lesion.

At a microscopic level, the microcomedone looks like a tiny little pouch filled with oil, bacteria, and dead skin cells ^[3] and is usually only present on acne-prone skin.

In fact, it is estimated that, in any area of visibly clear skin on an individual with acne-prone skin, up to 30% of the pores would be classed as microcomedones or subclinical acne. This is in comparison to 0.25% of the pores that are involved in visible acne lesions – even in fairly severe cases of acne ^[4].

This basically means that active acne is only present in a very small percentage of pores at any one time, even in very severe cases of acne, with the majority of acne being subclinical or inactive.

How To Get Rid Of Subclinical Acne

Even though there are various different interpretations of what subclinical acne actually is (microcomedones vs whiteheads vs forehead bumps etc.), when it comes to how to treat it, the treatment options are very similar and mainly involve controlling oil production and increasing skin cell turnover.

Skincare ingredients that can help reduce oil production include:

• Niacinamide
• Green Tea
• Centella Asiatica
• Salicylic Acid
• Zinc
• Witch Hazel

Skincare ingredients that can help increase skin cell turnover include:

• AHAs (e.g. glycolic acid, lactic acid)
• BHAs (e.g. salicylic acid)
• Retinoids (e.g. retinol, retinaldehyde, retinoic acid, adapalene)

There is very little research about treatments for microcomedones. However, one clinical study found that 0.1% adapalene gel was able to reduce the number of microcomedones by over 50% when applied daily for 8 weeks ^[1]. This improvement was maintained with continued use of adapalene gel.

In fact, retinoids such as adapalene, tretinoin, and tazarotene are widely recommended for treating active acne as well as preventing the development of microcomedones and further acne breakouts ^[5].

Other Tips for Preventing Subclinical Acne

1. Wash your face twice a day – This will help ensure that all the dirt and debris that has built up throughout the day, as well as any makeup, is removed from the surface of the skin. Foaming cleansers are the best at removing dirt and oil from deep within the pores but can sometimes be drying on the skin which may lead to your skin overproducing oil to compensate.
2. Moisturize your skin – If you have acne-prone skin you may have been told that you don’t need to moisturize. However, research suggests that acne may be partially caused by a damaged skin barrier and dehydrated skin. Certain enzymes that are responsible for breaking the bonds between dead skin cells in order for them to be shed from the surface of the skin also require the skin to be adequately hydrated in order to function properly. This means that moisturizing your skin can help its natural exfoliation process.
3. Wear sunscreen every day – Aside from being the best thing that you can do to improve your skin’s health, regular sunscreen use may help reduce oil production. This is because too much UV exposure can lead to an overgrowth of oil glands and a temporary increase in the production of oil. Plus, some research suggests that free radicals, such as those produced on exposure to UV radiation may be partially responsible for acne.
4. Follow a low glycaemic index (GI) diet – While the link between diet and acne still remains controversial, some research suggests that following a low GI diet can improve the appearance of acne. This is because high GI foods cause a spike in blood insulin levels which, in turn, stimulates the hormones that cause increased oil production in the skin.
5. Reduce stress – Some research has demonstrated that stress levels are positively correlated with acne severity ^[6], which means that the higher a person’s stress levels are, the more severe their acne is likely to be. This is mainly down to the way that stress affects the hormones that stimulate oil production and inflammation.

Summary

Subclinical acne is not a true medical definition but refers to acne that is not currently active or visible. This type of acne is generally referred to as a ‘microcomedone’ which is the beginning of an acne lesion life cycle. Generally speaking, if your skin is prone to acne breakouts, it is highly likely that you also have subclinical acne.

To prevent and treat microcomedones, and thus subclinical acne, skincare should focus on reducing oil production and increasing skin cell turnover in order to prevent the pore(s) from becoming fully blocked.

The most effective treatments for this purpose are retinoids, particularly adapalene gel, but other skincare ingredients that may help include chemical exfoliants, niacinamide, and green tea.

References

1. Thielitz, A., Sidou, F. & Gollnick, H. (2007). ‘Control of microcomedone formation throughout a maintenance treatment with adapalene gel 0.1%’, J Eur Acad Dermatol Venereol., 21(6), 747-753. Available at: https://pubmed.ncbi.nlm.nih.gov/17567301/
2. Li, H. (2010). ‘Metagenomic study of the human skin microbiome associated with acne’, Nature Precedings. https://doi.org/10.1038/npre.2010.5305.1. Available at: https://www.nature.com/articles/npre.2010.5305.1.pdf
3. Josse, G., Mias, C., Le Digabel, J. et al. (2019). ‘High bacterial colonization and lipase activity in microcomedones’, Exp Dermatol, 29(2), 168-176. Available at: https://onlinelibrary.wiley.com/doi/full/10.1111/exd.14069
4. Saurat, J. (2015). ‘Strategic targets in acne: the comedone switch in question’, Dermatology, 231, 105-111. Available at: https://www.karger.com/Article/FullText/382031
5. Leyden, J., Stein-Gold, L. & Weiss, J. (2017). ‘Why topical retinoids are mainstay of therapy for acne’, Dermatol Ther., 7(3), 293-304. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5574737/
6. Chiu, A. Chon, S. & Kimball, A. (2003). ‘The response of skin disease to stress: changes in the severity of acne vulgaris as affected by examination stress’, Arch Dermatol., 139(7), 897-900. Available at: https://www.ncbi.nlm.nih.gov/pubmed/12873885/