Beyond the Face: An Exploratory Survey on Facial and Truncal Acne in High School Students

Abstract

Background

Acne vulgaris commonly affects both the face and trunk, yet truncal acne remains underrecognized and less studied in adolescents.

Objective

This study aimed to assess the prevalence, perceived severity, stress levels, treatment behaviors, and willingness to seek care in adolescents based on acne location.

Methods

A cross-sectional survey was conducted among 211 first-year high school students (104 males, 107 females) in Incheon, South Korea. A structured questionnaire captured data on acne location, severity, stress, treatment history, and willingness to seek care. Analyses included descriptive statistics, χ² tests, t-tests, and Spearman correlation.

Results

Facial acne was reported by 86.7% of participants and truncal acne by 47.4%. The presence of facial and truncal acne was significantly associated (p<0.05), with truncal acne developing approximately one year after facial acne onset (p<0.05). While the mean subjective severity scores for facial (1.61±0.63) and truncal acne (1.57±0.79) were similar (p>0.05), stress levels were significantly higher for facial acne (p<0.05). Treatment rates were substantially lower for truncal acne (17.6%) compared to facial acne (48.6%), despite comparable willingness to seek clinical care.

Conclusion

Truncal acne is common but undertreated in adolescents. Despite comparable willingness to seek care, actual treatment rates remain low, underscoring a critical gap in management. Given the significant co-occurrence and risk of sequelae, clinicians should routinely assess for truncal acne in adolescents with facial acne and adopt a holistic management strategy addressing both areas.

INTRODUCTION

Acne vulgaris is a common chronic inflammatory disorder of the pilosebaceous units, affecting a significant proportion of adolescents¹,². It typically involves sebaceous gland-rich areas such as the face, chest, and back³. Although facial acne receives considerable clinical and research attention, truncal acne—referring to acne lesions on the chest, shoulders, and back—remains underrecognized and underreported⁴,⁵.

Truncal acne can present with a variety of lesion types, including papules, pustules, nodules, and comedones, similar to facial acne⁶. However, its location often makes it less visible to others, leading to lower rates of self-reporting, delayed treatment, and increased risk of complications such as scarring and post-inflammatory hyperpigmentation⁷,⁸,⁹. Despite its concealability, truncal acne may impose a comparable psychological burden, affecting self-esteem, body image, and social behavior, particularly in adolescents¹⁰.

Studies indicate that truncal acne frequently coexists with facial acne, with truncal lesions often developing after facial outbreaks¹¹. Contributing factors such as stress, hormonal changes, occlusive clothing, sweat, and poor hygiene practices can exacerbate truncal involvement¹². Yet, due to its relative neglect in clinical assessment and research, many aspects of truncal acne—including its epidemiology, psychosocial impact, and treatment patterns—remain poorly understood.

This study aims to explore the subjective severity, stress levels, and treatment intentions associated with both facial and truncal acne in high school students. By examining survey data from adolescents, we seek to highlight the often-overlooked burden of truncal acne and to advocate for more holistic and inclusive management strategies that address the full spectrum of acne involvement. To our knowledge, this is the first survey to specifically investigate truncal acne among Korean adolescents. In addition, by simultaneously evaluating treatment history and willingness to seek professional care, our study uniquely highlights the discrepancy between treatment intention and actual behavior, which has rarely been reported in this age group.

MATERIALS AND METHODS

This study aimed to evaluate the prevalence, severity, treatment behaviors, and psychosocial impact of facial and truncal acne among adolescents. An exploratory cross-sectional survey was conducted on June 7, 2023, targeting first-year high school students in Incheon, South Korea. The study was approved by the Ethics Committee of Incheon St. Mary’s Hospital, The Catholic University of Korea (approval number OC21TISI0158).

A total of 212 students (105 boys and 107 girls) completed the questionnaire. The self-administered survey collected data on the presence and perceived severity of facial and truncal acne, using a 4-point scale: mild, moderate, severe, and very severe. Participants also rated their stress related to acne using a numeric rating scale (NRS) from 0 to 10, where higher values indicated greater stress. Additional items assessed acne treatment history (ongoing or past), treatment types, and willingness to seek treatment (Appendix 1).

Descriptive statistics were used to analyze prevalence and treatment patterns. Independent t-tests compared continuous variables between sexes, and χ² tests assessed categorical variables. A Spearman rank-order correlation was performed to assess the relationship between facial and truncal acne severity. Statistical analyses were conducted using SPSS Statistics, version 29.0 (IBM Corp., Armonk, NY, USA).

RESULTS

Prevalence and subjective severity of acne according to location (face vs. trunk)

Of the 211 students surveyed, 86.7% reported having facial acne (male: 86.5%, female: 86.9%, p>0.05) while 47.4% reported truncal acne (male: 49.0%, female: 45.8%, p>0.05). The presence of facial and truncal acne was significantly associated (χ² test) with 43.9% of students experiencing both (p<0.05) (Table 1).

Table 1. Survey results.

Variables		Total (n=211)	Male (n=104)	Female (n=107)	p-value
Prevalence of acne according to its location
	Facial acne	183 (86.7%)	90 (86.5%)	93 (86.9%)	>0.05
	Truncal acne	100 (47.4%)	51 (49.0%)	49 (45.8%)	>0.05
Subjective severity of acne according to its location*
	Facial acne	1.61±0.63	1.70±0.66	1.53±0.60	>0.05
	Truncal acne	1.57±0.79	1.58±0.85	1.57±0.74	>0.05
	p-value	>0.05	>0.05	>0.05
Age of onset according to acne location
	Facial acne	13.3±1.24	13.7±1.27	12.9±1.08	>0.05
	Truncal acne	14.3±1.39	14.4±1.57	14.2±1.17	>0.05
	Mean difference (F-T)	−1.00	−0.72	−1.36
	p-value	<0.05	<0.05	<0.05
Stress level according to acne location
	Facial acne	4.58±2.71	4.38±2.78	4.76±2.63	>0.05
	Truncal acne	3.59±2.70	3.37±2.80	3.84±2.60	>0.05
	Mean difference (F-T)	+0.99	+1.01	+0.92
	p-value	<0.05	<0.05	<0.05
Treatment history of acne according to its location
	Facial acne	48.6%	40%	57%	<0.05
	Truncal acne	17.6%	15.4%	20%	>0.05
	p-value	<0.05	<0.05	<0.05
Willingness to visit the clinic according to acne location
	Facial acne	53.5%	45.9%	60.9%	<0.05
	Truncal acne	45.9%	37.3%	55.3%	>0.05
	p-value	>0.05	>0.05	>0.05

Values are presented as number (%) or mean ± standard deviation.

^*Mild 1; Moderate 2; Severe 3; Very Severe 4.

Regarding acne severity (mild 1, moderate 2, severe 3, very severe 4), the mean subjective severity of facial acne was 1.61±0.63 (male: 1.70±0.66, female: 1.53±0.60, p>0.05). The mean subjective severity of truncal acne was 1.57±0.79 (male: 1.58±0.85, female: 1.57±0.74, p>0.05) showing little difference from facial acne (p>0.05) (Table 1). There was no significant correlation between the severity of facial and truncal acne (rho=0.160, p=0.124).

Age of onset according to acne location (face vs. trunk)

The mean age of onset of facial acne was 13.3±1.24 years (male: 13.7±1.27, female: 12.9±1.08, p>0.05) and truncal acne 14.3±1.39 years (male: 14.4±1.57, female: 14.2±1.17, p>0.05). Truncal acne developed approximately one year after the onset of facial acne, and this difference was statistically significant (p<0.05). Participants who could not recall their age of onset were excluded from this analysis (Table 1, Fig. 1).

Fig. 1. Age of onset distribution (facial acne vs. truncal acne).

Stress level according to acne location (face vs. trunk)

Stress levels, measured using the NRS, varied between facial and truncal acne. For facial acne, the mean stress NRS was 4.58±2.71 (male: 4.38±2.78, female: 4.76±2.63, p>0.05). For truncal acne, the mean stress NRS was 3.59±2.70 (male: 3.37±2.80, female: 3.84±2.60, p>0.05). The level of stress significantly differed between facial acne and truncal acne with facial acne causing more stress (p<0.05) in both males and females (Table 1, Fig. 2).

Fig. 2. Stress level (numeric rating scale; range 0–10) distribution (facial acne vs. truncal acne).

Treatment history of acne according to location (face vs. trunk)

Participants reported differing treatment histories for facial and truncal acne. For facial acne, 48.6% (male: 40%, female: 57%, p<0.05) had received some form of treatment, compared to only 17.6% for truncal acne (male: 15.4%, female: 20%, p>0.05) (Table 1). The most common treatments for facial acne included topical medication (32.6%), anti-acne cosmetics (21.2%), acne extraction (14.7%), and oral medication (10.9%). In contrast, truncal acne treatments were primarily limited to topical agents (12.7%) and anti-acne cosmetics (6.9%). Notably, laser or intralesional steroid injections were used exclusively for facial acne (5.4%) (Supplementary Table 1).

Willingness to visit the clinic according to acne location (face vs. trunk)

Participants expressed willingness to visit a clinic for facial acne in 53.5% of cases, (male: 45.9%, female: 60.9%, p<0.05) and for truncal acne in 45.9% (male: 37.3%, female: 55.3%, p>0.05) (Table 1). Among those willing to seek care, topical agents were the most preferred treatment option for both facial (26.6%) and truncal acne (29.4%), followed by cosmetic procedures (lasers, local injection, acne extraction), anti-acne cosmetics, oral medication for facial acne; and cosmetic procedures, oral medication and anti-acne cosmetics for the trunk (Supplementary Table 1).

DISCUSSION

This study offers an in-depth evaluation of facial and truncal acne among adolescents, emphasizing the need for comprehensive acne assessment in both clinical and public health contexts. While facial acne remains more frequently recognized and treated, truncal acne affected nearly half of the surveyed population (47.4%) and was significantly associated with facial acne (43.9% comorbidity), yet it remained markedly undertreated. Contrary to previous reports⁵,⁸,¹¹,¹³,¹⁴, our findings did not reveal any sex-based differences in the prevalence of truncal acne.

Despite comparable self-reported severity between facial and truncal acne, the psychosocial burden was greater for facial lesions, likely due to their visibility and the perceived social stigma. Nevertheless, truncal acne is not without psychological impact¹⁰,¹⁵,¹⁶, and its concealability should not lead to clinical neglect—particularly given its higher risk for hypertrophic and keloid scarring, on the back and chest where dermal tension and collagen density are higher¹⁷. Chronic inflammation is a known driver of exaggerated scarring responses¹⁸, underscoring the importance of early identification and treatment of truncal acne to prevent long-term sequelae. This is particularly important for males with darker skin tones, who are more prone to truncal scarring and post-inflammatory hyperpigmentation⁷,¹⁹. Beyond psychosocial aspects, our findings provide new insights into the clinical course of acne by demonstrating that truncal acne tends to develop about one year later than facial acne. This temporal difference in age of onset has not been well characterized in previous adolescent cohorts and may have implications for anticipatory guidance and early intervention.

A key clinical finding from this study is the notable discrepancy between willingness to seek treatment and actual treatment behavior: although nearly half of the participants with truncal acne expressed willingness to receive treatment, only 17.6% had undergone any form of management. This highlights a persistent gap in the awareness and prioritization of truncal acne by both patients and healthcare providers, potentially resulting in delayed and suboptimal care. Importantly, this survey reveals an underrecognized treatment gap in truncal acne, where willingness to seek medical care did not translate into actual treatment. This mismatch underscores the need for targeted education and proactive inquiry by clinicians. Furthermore, effective management of truncal acne often requires longer treatment durations and systemic therapies—such as oral antibiotics or isotretinoin—due to the anatomical challenges of topical application and the larger surface area involved⁸,¹¹,²⁰. The management of truncal acne is often complicated by both anatomical and external factors. The larger surface area and difficulty of topical application frequently necessitate longer treatment durations²¹, while increased sebum production, sweat accumulation, occlusion from tight clothing or sports equipment, and repetitive friction on the chest and back can exacerbate inflammation and promote scarring²². These combined challenges help explain why systemic therapies such as oral antibiotics or isotretinoin are often required in moderate-to-severe truncal acne. In this cohort, treatment was primarily limited to topical agents and over-the-counter anti-acne cosmetics, which are often insufficient for managing moderate-to-severe truncal acne²³.

Overall, these findings support the need for dermatologists to routinely inquire about truncal involvement during acne evaluations and to educate patients on the importance of seeking professional care, especially when over-the-counter treatments fail. A comprehensive, site-inclusive approach is essential to improving clinical outcomes and enhancing patient satisfaction. Dermatologists should not overlook “invisible areas” like the trunk, where lesions may be hidden but clinically significant, and systematically include truncal assessment in routine acne evaluations.

This study has several limitations. First, its reliance on self-reported questionnaires may have introduced recall or reporting bias, and the absence of direct physician assessment limits diagnostic precision. Second, the study population was restricted to first-year high school students in a single urban area, which reduces generalizability. Third, the diagnosis of truncal acne was not clinically confirmed by dermatologists prior to survey completion, raising the possibility of misclassification (e.g., folliculitis). Future studies should incorporate standardized clinical assessments, objective acne grading, and microbial testing to better characterize truncal eruptions and distinguish them from other dermatoses.

Truncal acne remains an underestimated health issue that imposes both physical and significant psychological burden. This survey offers the first insight into adolescents’ perceptions of truncal acne in Korea, underscoring the urgent need for educational outreach and the reinforcement of both medical and psychological support for this population. Enhancing awareness among patients, parents, and clinicians alike is key to addressing the full spectrum of acne-related burden.

In conclusion, truncal acne remains an underestimated health issue in Korean adolescents. Our survey emphasizes the clinical relevance of routinely screening for truncal involvement in patients presenting with facial acne and adopting holistic management strategies that address both anatomical sites. Bridging the gap between willingness and actual treatment is essential to reduce long-term sequelae and improve patient outcomes.

Appendix 1

Survey on perception of facial and truncal acne

SUPPLEMENTARY MATERIAL

Supplementary Table 1

Survey results with regards to treatment