SHORT COMMUNICATION
Anni TELKKÄLÄ1, Jari JOKELAINEN2, Terhi PILTONEN3, Laura HUILAJA1 and Suvi-Päivikki SINIKUMPU1*
1Department of Dermatology, University Hospital of Oulu, Oulu, and Medical Research Center, Research Unit of Clinical Medicine, University of Oulu, Oulu, 2Northern Finland Birth Cohorts, Arctic Biobank, and Infrastructure for Population Studies, University of Oulu, Oulu, and 3Department of Obstetrics and Gynecology, University Hospital of Oulu, Oulu, and Medical Research Center, Research Unit of Clinical Medicine, University of Oulu, Oulu, Finland. *E-mail: suvi-paivikki.sinikumpu@oulu.fi
Citation: Acta Derm Venereol 2025; 105: adv44151. DOI: https://doi.org/10.2340/actadv.v105.44151.
Copyright: © 2025 The Author(s). Published by MJS Publishing, on behalf of the Society for Publication of Acta Dermato-Venereologica. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (https://creativecommons.org/licenses/by-nc/4.0/).
Submitted: Jun 16, 2025. Accepted after revision: Oct 6, 2025. Published: Oct 29, 2025.
Competing interests and funding: The authors have no conflicts of interest to declare.
Acne vulgaris is an inflammatory skin condition that is becoming increasingly frequent in adults (1, 2). Cases affecting individuals over the age of 25 years are termed post-adolescent or adult acne (2). Adult acne can affect both men and women with a higher reported frequency in women (2). The prevalence of adult female acne at the age of 30 has varied between 26% (3) and 35% (4) depending on the study design. Adult acne is often localized on the chin and around the mouth (2). About 50% of patients also have acne on their body (1, 2).
Adult acne is less studied than adolescent acne, and truncal acne in particular has been the focus of little research (5). Moreover, studies on acne have mainly been based on self-assessment rather than evaluation by a dermatologist (4, 6) and there is a lack of understanding of how consistent self-assessment and dermatologist evaluation are. We aimed to study the prevalence of adult female acne, patients’ clinical characteristics, and their patterns of treatment-seeking, as well as self-assessments of acne with evaluations performed by dermatologists.
This study analyses data from the women’s health study (WENDY) including women in their 30s (7). As a part of WENDY, each participant’s face and back were photographed in the absence of cosmetic products. An experienced dermatologist (SPS or LH) evaluated 3 images of the face (straight-on and from each side) and 1 image of the back, with the option of zooming in. The distribution of facial acne lesions was categorized into 4 areas. Acne severity was graded according to the Global Acne Grading System (8) and categorized as “no acne”, “almost clear”, “mild”, “moderate”, and “severe”. “No acne” and “almost clear” were combined as “none”.
As part of a larger health questionnaire, participants were asked “Do you currently have acne?” (“No”/“Yes”). After that they used the modified Visual Analog Scale (VAS) to self-rate the severity of their current acne from “no acne at all” to “very severe acne” (scale converted to 0–100). Acne treatments were self-reported via the question “Are you currently using the following treatments for your acne: topical treatments available without prescription, doctor prescribed topical treatments, systemic antibiotics and/or isotretinoin?” (“No”/“Yes”).
Acne prevalence (face and back) based on clinical evaluation was expressed as a percentage. Participants’ self-rated acne severity was summarized using the mean, standard deviation (SD), and 95% confidence intervals (CI). Agreement between self-reported and clinically evaluated acne was assessed by calculating sensitivity and specificity with corresponding 95% CIs. The interobserver reliability was performed between SPS and LH by using a Kappa statistic for observed agreement between paired examiners. The level of reliability was high (0.87–100.0). Statistical analyses were performed using R (version 4.2.2; R Core Team, Vienna, Austria) within RStudio (version 2023.03.1 Build 446; RStudio, PBC, Boston, MA, USA).
A total of 5,404 women were invited to the study, and 1,918 (35%) participated. Of these, 51 declined to be photographed; thus, the final study population included 1,867 participants. The mean age of the study cases was 35.3 years. The demographics of the WENDY participants have been presented elsewhere (7).
Acne was present in 585 (31.3%) participants. Facial acne was more common than back acne, and most cases were classified as mild.
Lesions were most commonly seen on the chin and least commonly on the nose. Acne severity was unrelated to lesion locations. Of all 478 participants with facial acne, lesions were most often located in 2 areas (40.2%) (Table I).
| Acne overall*, n (%) | 585 (31.3) | ||||
| Acne on face, n (%) | 478 (25.6) | ||||
| Distribution of acne on face, n (%) | |||||
| In 1 area | 25.3% | ||||
| In 2 areas | 40.2% | ||||
| In 3 areas | 27.8% | ||||
| In 4 areas | 6.7% | ||||
| On chin | 91.4% | ||||
| On cheeks | 69.2% | ||||
| On nose | 21.8% | ||||
| On forehead | 33.5% | ||||
| Acne on back, n (%) | 220 (11.8) | ||||
| Acne on both face and back, n (%) | 113 (6.1) | ||||
| Facial acne only, n (%) | 365 (19.6) | ||||
| Severity, n (%) | |||||
| Mild | 84.1% | ||||
| Moderate | 14.0% | ||||
| Severe | 0.3% | ||||
| Back acne only, n (%) | 107 (5.7) | ||||
| Severity: | |||||
| Mild | 85.0% | ||||
| Moderate | 15.0% | ||||
| Severe | 0% | ||||
| *Acne on either face or back. | |||||
For self-reporting of overall acne the sensitivity was 0.35 (95% CI 0.30–0.39) and the specificity 0.96 (95% CI 0.94–0.97). Corresponding values for back acne only were 0.24 (95% CI 0.12–0.39) and 0.96 (95% CI 0.94 –0.97), respectively. The mean VAS score increased with the severity of the dermatologist’s assessment, being lowest for mild acne and highest for severe acne (Fig. S1).
Oral antibiotics and isotretinoin were rarely used across all severity levels, and topical treatments were also infrequently used despite being more common (Table SI). Treatment use was slightly more common in individuals with facial acne than those with back acne (data not shown).
In the present study the prevalence of acne was 31.3%. This finding aligns with that of a large cross-sectional US study of women (n = 2,895), which evaluated acne from photographs and found 26% prevalence of acne among women aged 31–40 (3).
Almost a fifth of our cases had acne only on the face, mostly on the chin and cheeks. Correspondingly, the lower facial region has been shown to be a common site of acne in adult women in other study too (2). Back acne was present in over 10% of our participants. This indicates that the back is a rather common site for acne in adults; however, precise prevalence rates for back acne alone are lacking. Our findings highlight the importance of examining the entire skin in acne patients to ensure that back acne is not overlooked. Similarly to facial acne, back acne contributes to the psychosocial burden and may result in scarring – and further poorer emotional well-being – if not properly treated (5).
We found that acne was poorly recognized by participants; this was particularly true of those with back acne. In line with ours, previous studies have reported that sensitivity and specificity in self-reported acne has been relatively poor (9) and an individual’s own assessment of acne severity may differ from that of a dermatologist (10). Nevertheless, although our participants poorly recognized their own acne, their assessment of acne severity often matched that of the dermatologist. The lack of recognition of acne may be one of the reasons why the disease is under-treated (11). Other possible reasons include lack of knowledge on how to seek help, ineffectiveness, and the cost of treatment (11). Furthermore, social media users are increasingly turning to platforms such as TikTok for information on various kinds of skincare (12), which could reduce the number of visits to physicians for acne. On the other hand, social media could be utilized even more, especially by dermatologists, for sharing accurate information concerning adult acne. This might, for example, guide acne patients to initiate self-treatment earlier as effective over-the-counter topical products for mild acne are available.
The major strength of this study is the data of unselected subjects and the evaluation performed by dermatologists. As a limitation, the study population represented predominantly white Finnish subjects in their 30s, and thus the findings may not be generalized to other age groups or ethnicities. Furthermore, acne was assessed from photographs, which may have led to over- or underestimation in some cases. Finally, not all invited subjects participated in the study or answered all questions, leading to some missing data.
In conclusion, the results of this study suggest that female adult acne is a common disease affecting about one-third of women to some extent. Its clinical pattern seems to differ slightly from that of teenage acne, focusing more often on the chin but also on the back. Interestingly, we found that acne was poorly self-recognized, which probably represents a factor driving undertreatment of acne. However, it is important that those with mild acne also have treatment, as even mild acne can negatively affect an individual’s mental health (5, 13). To increase awareness of adult acne, it would be advisable for general practitioners and dermatologists to raise the topic of adult acne even when it is not the patient’s primary reason for seeking care.
The authors would like to thank all cohort members and researchers who participated in the NFBC 1986 and WENDY study. They would like to express their special thanks to Riikka Arffman, Marika Kangasniemi, Jenni Kinnunen, Eetu Kiviniemi, Kaisu Luiro, Susanna Savukoski, and Maria Rajecki. They also wish to acknowledge the work of the NFBC Project Center.
Availability of data and materials: The WENDY data are available upon request from the NFBC cohort centre under certain conditions. The data can be requested from the NFBC cohort centre, and the request will be directed to the WENDY research team. To support and encourage research collaborations, additional information can be found on the study’s webpage at https://www.oulu.fi/en/womens-health-study-wendy-protocolpopulation-based-study-assessing-gynecological-and-metabolic. All previously collected data of NFBC1986 can be found in the NFBC cohort catalogue at https://www.oulu.fi/en/university/faculties-and-units/faculty-medicine/northern-finland-birthcohorts-and-arctic-biobank/northern-finland-birth-cohorts.
Ethics approval and consent to participate: The Ethical Committee of the Northern Ostrobothnia Hospital District approved the study (115/2012), which was performed according to the principles of the Helsinki Declaration of 1983. Informed written consent to participate was obtained from all study participants.
IRB statement: The study was approved by the Ethics committees of Northern Ostrobothnia (49/2019) and Helsinki and Uusimaa (483/2020).