by Social media is full of questionable advice. But one of the latest skincare hacks some users are sharing online is seriously concerning.
Some content creators on TikTok claim that sunscreen or spending time in the tanning bed helps get rid of acne.
Although natural sunlight and UV rays have long been used to treat skin conditions, evidence shows that these techniques are ineffective when it comes to treating acne. Not to mention, the risks of overexposure to UV far outweigh any benefits you might see in the appearance of your skin.
Phototherapy is a medical treatment in which the skin is exposed to sunlight or UV radiation in a controlled environment. It is widely used to treat psoriasis and eczema in cases where other treatments have not worked or when other treatments are not compatible for a patient.
Research shows that phototherapy can help reduce inflammation and suppress the skin’s immune response – both key factors in the development of these conditions.
However, it is important to note that this procedure is performed in a clinical setting where the radiation doses used on the skin are carefully controlled to minimize the harmful effects of UV exposure. Pre-treatment tests are also carried out to reduce the risk of combustion.
But in the case of acne, there is little evidence that UV exposure is beneficial.
A 2023 retrospective cohort study of 19,939 participants, which looked at their six years of UV exposure before enrollment, found that long-term exposure to relatively low levels of UVB (a type of invisible radiation emitted by the sun) every day (approximately an hour) was associated with a reduced risk of moderate to severe acne in young adults.
But there were many limitations to the study. The precise doses of UV to which the participants were exposed were not measured directly. 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 take into account the negative implications of exposure.
Studies on human skin cells have also shown some potential benefits of UVB rays, including killing them Propionibacterium acnesthe bacteria 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 likely minimal and not sufficient for therapeutic use – especially given the negative side effects of UV radiation.
A 2023 narrative review of all studies conducted between 1992 and 2022 on sun exposure and acne found that UV exposure is unlikely to improve acne symptoms.
And in some cases it can even make acne worse. This may be because exposure to UVB radiation can activate immune cells that worsen the inflammation that acne causes and increase sebum production – a known risk factor for acne.
Risks of sunburn
Not only is there no evidence that the sun can treat acne, there are also many well-studied disadvantages of sun exposure, such as a significantly increased risk of skin cancer.
Studies show that even one incident of blistering sunburn in childhood or adolescence can double the risk of developing skin cancer later in life. The risk of developing skin cancer increases the more often you burn. This is due to the fact that UV exposure causes significant DNA damage in our skin cells.
Exposure to UV radiation also contributes significantly to premature skin aging. 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 is important to:
- Use a broad-spectrum sunscreen with at least SPF 30 and reapply 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.
Currently, the most effective acne treatments are those that you can buy at the pharmacy or that are 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 derivative of vitamin A. It reduces the oils in the skin (sebum), skin bumps and the amount of acne-causing bacteria in the skin. Isotretinoin is very effective at healing acne lesions (by 85 percent in one study after four months of use). Only about a quarter of patients who use it require a second course of treatment.
Although these treatments are effective, some acne patients may seek alternative treatments due to the drug’s side effects (namely mood swings).
But a recent study of more than 30,000 isotretinoin patients found no link between isotretinoin and mood swings, suggesting this side effect is extremely rare.
It is important to note that anyone prescribed acne medication should be careful when going out in the sun. Isotretinoin and tetracyclines (a class of antibiotics) can be photosensitizers and cause even greater damage when the skin is exposed to the sun. One study reported that between 20 and 40 percent of acne patients taking a common type of tetracycline experienced photosensitivity.
That’s why it’s important to wear sunscreen when you go outside on sunny days. Not only will it protect your skin and lower the risk of skin cancer, there is also some evidence that using sunscreen can benefit people with acne by reducing inflammation in skin cells and reducing light sensitivity.
Overall, several effective, safe options to treat acne already exist. If you are considering using the sun or a tanning bed to treat the condition because you think your current treatment is not working, it is important to talk to your doctor rather than risk 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.
