Prevalence and Demographics of Truncal Involvement Among Acne Patients: Survey Data and a Review of the Literature.

Background: Truncal acne is frequently underdiagnosed despite affecting around half of those with facial acne. The objective was to provide an overview of the literature on the incidence of truncal acne according to age, gender, and acne severity. Methods: A narrative review of data from recent large surveys and a literature search in PubMed on the incidence of truncal acne across subgroups of age, gender, and acne severity. Results: The prevalence of truncal acne alone was low, ranging from <1% to 14%, but approximately 30 to 60 percent of individuals with facial acne also had truncal acne depending on the population. In an online survey in the United States of 2,000 respondents aged between 14 -29 years with self-reported active facial and/or truncal acne, the incidence of truncal acne was lower in the 14-20 years subgroup than in the 21-29 years subgroup (49% vs 54%). The incidence of truncal acne was similar in both males and females, while 46 percent of respondents with self-declared clear and mild acne indicated having truncal involvement compared to 60 percent of those with moderate or severe acne. Limitations: Online surveys have inherent limitations, such as self-reporting and potential confounders. Conclusion: Data suggests that patients with both facial and truncal involvement have earlier onset of acne and more severe acne. Additional adverse psychological impact may arise from having the impression that the disease is spreading and becoming more severe. Raising awareness of truncal acne prevalence and demographics could improve its clinical management to reduce the negative psychological impact.