By Karl Lawrence, King’s College London; Wisam Alwan, King’s College London; The Conversation
Studies show that even just one incidence of a blistering sunburn in childhood or adolescence can double the chances of developing skin cancer later in life. (Pexels Photo)
Social media is full of questionable advice. But one of the latest skincare hacks some users are sharing online is seriously worrying. Some content creators on TikTok are claiming that getting a sunburn or spending time in a tanning bed will help get rid of acne.
While natural sunlight and UV radiation have long been used to treat skin conditions, the evidence shows these techniques aren’t effective when it comes to treating acne. Not to mention that the risks of excess UV exposure far outweigh any benefits you might see in the appearance of your skin.
Phototherapy is a medical treatment that involves exposing the skin to sunlight or UV radiation in a controlled environment. It’s widely used to treat psoriasis and eczema in cases where other treatments haven’t worked or if other treatments aren’t compatible for a patient. Research shows phototherapy can help reduce inflammation and suppress the skin’s immune response – both key factors in the development of these conditions.
It’s important to note, however, that this procedure is done in a clinical setting where the doses of radiation used on the skin are controlled precisely to minimise the harmful effects of UV radiation exposure. Pre-treatment tests are also performed to reduce the risk of burning.
But in the case of acne, there’s little evidence that UV exposure is beneficial.
One 2023 retrospective cohort study of 19,939 participants, which looked at their previous six years of UV exposure prior to enrolment, did find that long-term exposure to relatively low-levels of UVB (a type of invisible radiation that’s emitted by the sun) each day (around one hour) was associated with a decreased risk of moderate to severe acne in young adults.
But there were many limitations to the study. The precise doses of UV the participants were exposed to was not directly measured. Instead, it was based on calculations done using location and weather data to understand how much sunlight participants were exposed to. This study also did not consider the negative implications of exposure.
Studies in human skin cells have also shown some potential benefits from UVB rays – including killing Propionibacterium acnes, the bacterium thought to be responsible for acne. But these benefits have only been shown in cells and have never been replicated in human studies. Most of these studies also concluded that any beneficial effect was probably minimal and not sufficient for therapeutic use – especially considering the negative side-effects of UV radiation.
A 2023 narrative review of all the studies conducted on sun exposure and acne between 1992 and 2022 has found that exposure to UV radiation is unlikely to improve acne symptoms. And, in some cases, it may actually worsen acne. This may be because exposure to UVB radiation can activate immune cells which worsen the inflammation acne causes and increase sebum production – a known risk factor for acne.
Sunburn risks
Not only is there no evidence that the sun can treat acne, there are also many well-studied downsides from sun exposure – such as a significantly increased risk of skin cancer.
Studies show that even just one incidence of a blistering sunburn in childhood or adolescence can double the chances of developing skin cancer later in life. The risk of developing skin cancer increases the more often you get sunburned. This is due to the fact that UV exposure causes significant DNA damage in our skin cells.
UV exposure is also a significant contributor to premature skin ageing. This is because it damages the collagen and elastin in the skin which can then lead to sagging and wrinkles.
When going out into the sun, it’s important to:
- Use broad-spectrum sunscreen with at least SPF 30 – reapplying every two hours or after swimming or sweating.
- Seek shade, especially during peak sun hours (typically 10am to 4pm).
- Wear protective clothing, including wide-brimmed hats and UV-blocking sunglasses.
At the moment, the most effective acne treatments are those which can be purchased at the pharmacy or prescribed by your doctor.
Severe acne can be treated with oral antibiotics that have an anti-inflammatory effect. Isotretinoin may also be prescribed. This is a synthetic derivitive of vitamin A. It reduces oils in the skin (sebum), skin bumps and the amount of acne-causing bacteria in the skin. Isotretinoin is highly effective in clearing acne lesions (by 85% in one study after four months of use). Only around one-quarter of patients who use it require a second course of treatment.
While these treatments are effective, concerns about the drug’s side-effects (namely mood changes) may be why some acne sufferers are seeking out alternative treatments. But a recent study of over 30,000 isotretinoin patients found no association with isotretinoin and mood changes, suggesting this side-effect is extremely rare.
It’s important to note that anyone prescribed acne medication should be careful when going out into the sun. Isotretinoin and tetracyclines (a class of antibiotics) can act as photosensitisers, causing even greater damage when the skin is exposed to the sun. One study reported that between 20-40% of acne patients taking a common type of tetracycline experienced photosensitivity.
This is why it’s important to wear sunscreen when going outside on sunny days. Not only will it protect your skin and lower your risk of skin cancer, some evidence also shows sunscreen use can benefit people with acne by reducing inflammation in the skin’s cells and reducing photosensitivity.
Overall, several effective, safe options to treat acne already exist. If you’re considering using the sun or a tanning bed to treat it because you feel your current treatment isn’t working, it’s important to speak with your doctor instead of putting yourself at risk of complications.
Karl Lawrence, Research fellow, King’s College London and Wisam Alwan, Clinical Research Fellow in Dermatology at King’s College London/Consultant Dermatologist Guy’s and St. Thomas’ NHS Foundation Trust, King’s College London
This article is republished from The Conversation under a Creative Commons license. Read the original article.
