Mostly a myth. The sun does not cure acne. It seems to improve it for a few weeks, through two temporary effects: the tan masks the lesions, and ultraviolet light appears to reduce inflammation in the short term.
Mostly a myth. The sun does not cure acne. It seems to improve it for a few weeks, through two temporary effects: the tan masks the lesions, and ultraviolet light appears to reduce inflammation in the short term. The skin then responds by producing sebum to excess and by thickening the horny layer, and the acne returns, often more severe. The phenomenon has a name in dermatology: the post-actinic eruption.
The sun has beneficial effects on the body, but where acne-prone skin is concerned there are several things to bear in mind. We have prepared a guide to everything you should know about sun exposure if you have acne.
Myths about acne and sun exposure:
What is said about the sun and acne | Answer | Why |
|---|---|---|
| The sun dries up spots | Partly true | The effect is real, but it is temporary and turns against the skin after a few weeks |
| The sun cures acne | Myth | It treats none of the causes of acne; it only masks the lesions |
| A tan makes the skin look better | True, but deceptive | It evens out the tone and masks the redness. When the tan fades, the acne is still there |
| The sun darkens the marks left by spots | A dangerous myth | Quite the opposite: ultraviolet light darkens the marks and makes them harder to treat |
| Sunscreen gives me spots, so I do not use it | Myth | The problem is the formula, not the sun protection. There are non-comedogenic products |
| A sunbed has the same beneficial effect | Myth | The same ultraviolet light, the same effects, plus a higher risk of skin cancer |
Does the sun really dry up spots?
Partly true. Although the sun may seem to dry spots up temporarily, UV radiation causes the skin to thicken and dry out and to produce sebum to excess to compensate, which blocks the pores and often leads to more severe eruptions later (the post-actinic eruption).
What happens in the skin when we are out in the sun
The rebound effect of acne after sun exposure has a clear physiological explanation, in four stages.
1. Dehydration and seborrhoea
The sun's rays dehydrate the skin. Even oily skin, producing sebum to excess, needs moisture. When excessive sun exposure dries the skin out, the sebaceous glands (which produce the sebum needed for natural lubrication) become overactive. This excessive production of sebum, called seborrhoea, is one of the key stages in the formation of acne lesions.
2. Cornification and the formation of blackheads and whiteheads
Another effect of dehydration is cornification (keratinisation): the layers of cells at the surface of the skin harden. This disturbs the natural process by which dead cells are shed and blocks the sebum from leaving the pores, leading to the formation of comedones (blackheads and whiteheads).
3. Sweating and blocked pores
In periods of high temperature, sweat production increases, and so does the speed at which it breaks down on the surface of the skin. Together with blocked pores, this creates an environment that suits the bacterium Cutibacterium acnes (formerly known as Propionibacterium acnes), associated with the appearance of acne.
4. The post-actinic eruption
The result of this chain is the post-actinic eruption: the acne returns after the summer, often more severe than before the exposure. It is exactly the opposite of what patients hoped for when they went to the beach “to dry their spots up”.
The sun pigments post-acne scars and marks
Exposure to ultraviolet light darkens the scars and marks left by acne, a phenomenon called post-inflammatory hyperpigmentation. The marks become darker and more persistent, and treating them is far harder than preventing them.
This is also why sun protection is not optional in acne: it is not merely an anti-ageing measure but part of the treatment of the marks and the scars.
Summer acne (acne aestivalis): spots on the back and shoulders after the sun
One of the commonest questions in summer is: why do spots appear on my back after the beach? The answer is often not ordinary acne but summer acne, also known as acne aestivalis or “Mallorca acne”, a kind of acne that appears specifically in summer and whose mechanism differs from that of ordinary acne.
The difference between acne vulgaris and summer acne
| Acne vulgaris | Summer acne (acne aestivalis) | |
|---|---|---|
| Trigger | Sebum, keratinisation, bacteria, hormones | Ultraviolet A radiation (UVA) |
| Comedones (blackheads) | Yes | No |
| Itching | Rarely | Yes, often intense |
| Typical location | Face, back, chest | Shoulders, arms, décolletage, back. The face is usually spared |
| When it appears | At any time | 1 to 3 days after the first intense sun exposure |
| Course | Chronic | Seasonal; it clears in winter |
Summer acne typically appears after the first intense sun exposure, on skin that has not been accustomed gradually to the sun. It clears by itself in winter and returns the following summer.
What helps: gradual exposure at the start of the season, avoiding rich products (oily sunscreens, beach oils, heavy lotions) and using light, non-comedogenic formulas. A treatment for acne vulgaris does not resolve summer acne, which is why the right diagnosis matters.
The positive effects of sun exposure
Moderate exposure to sunlight is good for the body and for the mind:
- Vitamin D: the sun is an important source of vitamin D, essential to numerous vital processes, among them the development of healthy bones.
- Mood: the body's ability to produce serotonin, often called the “happiness hormone”, is directly influenced by sunlight. Studies have shown that a lack of it can lead to seasonal affective disorder, a condition marked by low mood.
- The anti-inflammatory effect: ultraviolet radiation has an immunosuppressive and therefore anti-inflammatory effect, which explains the apparent improvement at the start.
Living with acne can be stressful, and if a little sun makes you feel better in your own skin, that counts. The condition is that the skin should be properly protected, because the risks of skin damage outweigh the benefits of unprotected exposure.
Note: acne treatments increase sensitivity to the sun
Many of the medicines prescribed for acne significantly increase the skin's tendency to burn in the sun:
- topical retinoids (tretinoin, adapalene);
- systemic retinoids (isotretinoin, known commercially as Roaccutane);
- the antibiotics used in treating acne;
- exfoliating acids (salicylic acid, acids of the AHA group).
If you are following such a treatment, sun protection becomes obligatory. Do not stop the treatment on your own initiative in order to go out in the sun: talk to your dermatologist, who can adjust the regime for the summer.
How to care for acne-prone skin in summer
With a simple, sound routine. You do not need ten products, but a few, used consistently.
In the evening
- Remove make-up with a micellar water suited to combination skin.
- Wash the face with a gentle cleansing gel.
- Apply the treatment product your dermatologist has recommended (with salicylic acid, tretinoin, benzoyl peroxide or another, according to severity), on clean, dry skin, in a very thin layer.
- Finish with a moisturiser.
In the morning
- Wash the face with lukewarm water.
- Reapply the moisturiser.
- Apply the last product: a sunscreen made for combination skin, with a light texture and broad spectrum (SPF 50+ and PA++++).
Make-up
Choose light foundations, with low or medium coverage, free of silicone. Prefer loose mineral powders, and avoid products with shimmer particles, which can block the pores.
Additional care
At the beginning and at the end of the summer it is a good idea to cleanse the skin with microdermabrasion, which removes the superficial layers of the skin and leaves a layer of new skin that absorbs creams better.
How to choose a sunscreen for acne-prone skin
The commonest objection from patients with acne is that “sunscreen gives me spots”. Most often the problem is not the sun protection itself but the formula chosen. Here is what to look for:
- A non-comedogenic label, or “does not clog pores”.
- Broad spectrum, with protection against UVA as well as UVB. SPF 50+ for acne-prone skin, especially if you are following a treatment.
- A light texture, fluid or gel, with no heavy oils and no rich formulas, which encourage the pores to become blocked.
- Fragrance-free, if your skin is reactive.
- Mineral filters (zinc oxide, titanium dioxide) if your skin is sensitive. Zinc oxide has anti-inflammatory properties as well.
For the body, especially if you have spots on your back, prefer sprays or light fluids rather than thick lotions and beach oils, which are among the main culprits behind summer acne.
If you have had a reaction to a sunscreen, that deserves a separate conversation with your dermatologist, because it may be an allergy to an ingredient rather than acne.
Do not expose skin affected by acne to the sun without sunscreen; always choose to relax under the parasol.
The Dermestetica doctor's advice
“Do not avoid the sun; learn to enjoy it safely. Prevention is always the best treatment.” – Dr Daniela Popoiu, specialist dermatovenereologist, Dermestetica
When to see a dermatologist
- your acne has worsened after the summer;
- spots have appeared on your back, shoulders or décolletage after sun exposure;
- the lesions itch and have no blackheads, which may point to summer acne rather than ordinary acne;
- dark marks have remained after the spots healed;
- you are following a treatment for acne and do not know how to go out in the sun safely;
- your sunscreen causes reactions or makes your acne worse.
FAQ – questions and other myths about acne and the sun
How long does it take for acne to return after the summer?
The post-actinic eruption usually appears a few weeks after the period of intense exposure, which is why many patients notice the worsening at the end of the summer and in the autumn.
Do sunbeds help acne?
No. A sunbed emits the same ultraviolet radiation and produces the same effects, plus a higher risk of skin cancer and premature ageing. It is not a safe alternative to the sun.
My sunscreen gives me spots. What should I do?
The problem is the formula chosen, not the sun protection itself. Choose a product labelled non-comedogenic, with a light texture and no heavy oils. Giving up sun protection is not a solution: it makes post-acne marks and scars worse.
What SPF do I need if I have acne?
At least SPF 30 for everyone, but for acne-prone skin, and especially during a dermatological treatment, SPF 50+ with broad spectrum (UVA and UVB) is recommended.
Can I take vitamin D if I avoid the sun?
Yes. Your vitamin D requirement can be met through diet and, where necessary, through supplements, on your doctor's recommendation. There is no need to expose yourself to the sun unprotected for that.
Why do spots appear on my back only in summer?
Most often this is summer acne (acne aestivalis), a reaction to UVA radiation, encouraged by rich beach products and by sweating. It appears 1 to 3 days after the first intense exposure and clears in winter.
Can I go to the beach if I am taking isotretinoin for acne?
Only with rigorous sun protection and with your dermatologist's agreement. Isotretinoin significantly increases the skin's tendency to burn. Do not stop the treatment on your own initiative.
Sources
- American Academy of Dermatology – Acne: Tips for managing: https://www.aad.org/public/diseases/acne/skin-care/tips
- American Academy of Dermatology – Back acne: How to see clearer skin: https://www.aad.org/public/diseases/acne/DIY/back-acne
- American Academy of Dermatology – Acne: Diagnosis and treatment: https://www.aad.org/public/diseases/acne/derm-treat/treat
- Mayo Clinic – Polymorphous light eruption: https://www.mayoclinic.org/diseases-conditions/polymorphous-light-eruption/symptoms-causes/syc-20355868