Acne Aestivalis
Acne aestivalis, also called Mallorca acne, is a distinctive type of acneiform eruption. It flares when the skin is exposed directly to ultraviolet light from the sun (particularly UVA), often in combination with skincare products or sunscreens that contain unsuitable lipids, oils and emulsifiers.
The condition is driven by a photochemical reaction between UVA and lipids on the skin, whether from natural sebum or from applied cosmetics. UVA promotes lipid peroxidation, producing free radicals and irritating intermediates at the opening of the hair follicle. This causes swelling of the follicular lining, disrupts keratinization in the follicular infundibulum and sets off acute inflammation that forms red papules. The condition has nothing to do with androgen-driven oil production or overgrowth of Cutibacterium acnes.
At Haute-Derma, our approach starts with a clinical assessment of the uniform inflammatory papules and a detailed look at your sun protection and summer skincare habits. From there, we build a plan to calm the inflammation, switch you to safe topical products and restore the skin barrier.
Clinical Features and Differential Diagnosis
Acne aestivalis is recognized by its particular appearance and seasonal pattern, which help separate it from ordinary acne (acne vulgaris) and from other sun-related rashes:
- Triggers and seasonality: Flares typically appear in summer, after beach holidays, outdoor activities or long sunbathing sessions in strong sun.
- Monomorphism: Crops of small, slightly raised red papules of uniform size (1–3 mm) appear all at once and rarely progress to large pustules or deep cysts.
- No comedones: There are no closed comedones (whiteheads) or open comedones (blackheads). This is the single most important clue for ruling out ordinary acne.
- Itching and burning: Unlike ordinary acne, which is rarely itchy or sore, the papules of summer acne are often intensely itchy, prickly or uncomfortably burning.
- Distribution: Mostly on sun-exposed skin such as the shoulders, upper chest, upper back, neck and outer forearms. The face is usually less affected than the trunk.
How Haute-Derma Diagnoses and Treats Acne Aestivalis
- Thorough diagnosis and identifying the irritant: The doctor examines the skin, noting the uniform red papules and how itchy or sore they are. We take a detailed history of your sun exposure, recent travel and the sunscreens or body lotions you have used, so the exact form of the condition can be pinned down.
- Stopping unsuitable lipid- and emulsifier-rich products: The key step is to stop rich cream sunscreens, oil-based products and emulsifiers prone to peroxidation right away. We switch you to lightweight gel or fluid sunscreens that are oil-free and emulsifier-free.
- Calming inflammation and relieving itch: The doctor prescribes gentle topical treatments and soothing, barrier-repairing solutions, along with a short course of oral antihistamines to control the itching and burning. Strong exfoliants such as high-strength BHA or tretinoin should be avoided, as they further irritate sensitized skin.
- Restoring the barrier and protecting against UV: We guide you through gentle cleansing with a soap-free wash and hydration with a light-textured moisturizer, and recommend physical sun protection (high-UPF clothing, wide-brimmed hats) to shield the healing skin from UVA.
Common Triggers and Clinical Presentations
| Trigger / Presentation | Mechanism and Clinical Features |
|---|---|
| Summer acne from oil-containing sunscreen | UVA interacts with lipids/emulsifiers in the sunscreen, causing lipid peroxidation. Crops of itchy, burning red papules appear on the shoulders and chest a few days after sun exposure. |
| Summer acne from the skin's own sebum | In very hot weather, UVA reacts with squalene and other lipids in natural sebum, producing small uniform papules on the back, chest and arms. |
| Inflamed, secondarily infected papules from scratching | Itchy papules are scratched repeatedly, leading to excoriations and secondary bacterial infection, with small pus points on top of the red papules. |
