Abstract
BACKGROUND: Truncal acne is common but underrecognized. Its pathogenesis is often considered similar to facial acne, so most studies and guidelines focus on facial involvement despite the substantial disease burden of truncal lesions. OBJECTIVE: This narrative review compares structural and physiological differences between truncal and facial skin, evaluates their impact on acne pathogenesis, and analyzes advantages and limitations of topical and systemic therapies, highlighting the role of routine skincare. METHODS: PubMed and Google Scholar were searched for English-language articles published up to December 2025 using keywords with Boolean operators. Evidence was narratively synthesized, and major study limitations were summarized. RESULTS: Truncal skin has a thicker stratum corneum, lower sebaceous gland density and activity, and site-specific differences in pH, sweat gland distribution, and microbiota, influenced by clothing occlusion and friction. These features are associated with deeper, more extensive lesions. Topical absorption may be limited and adherence reduced, while systemic treatments require careful balancing of efficacy and safety. Routine skincare may reduce adverse effects, improve adherence, and enhance topical outcomes. CONCLUSION: Management should consider skin-specific differences. Clinicians should assess truncal involvement and select formulations that optimize permeability and usability. Future research should clarify truncal-specific mechanisms and guide development of combination therapies and optimized topical formulations.