Tolerance and efficacy of an anti-blemish 360° soothing spray in individuals with truncal acne: results from a controlled study

Truncal acne is a frequent but under-recognized form of acne vulgaris affecting the back, chest, and shoulders, and can cause discomfort and psychosocial impact. Lesions include inflammatory papules and pustules, as well as non-inflammatory comedones, and treatment is often challenging due to thicker skin and difficulty of topical application. Given these specificities, suitable and well-tolerated formulations, easy to apply, especially in inaccessible areas, are essential to ensure adherence and long-term control of the condition. 

The objective of this study was to evaluate the tolerance and efficacy of an anti-blemish soothing 360° spray in subjects with mild to moderate truncal acne on the back, shoulders and neckline.

1. Woo, Y.R.; Kim, H.S. Truncal Acne: An Overview. J. Clin. Med. 2022, 11, 3660. https:// doi.org/10.3390/jcm11133660

This intra-individual controlled study took place in Brazil with panel consisted of 34 valid cases of teenagers and adults of both genders with mild to moderate acne severity on the face and trunc. Subjects acclimatized for at least 20 minutes at each visit (D0, D7, D14, D28, D56). At each visit, a dermatologist evaluated tolerance (erythema, oedema, dryness, desquamation, stinging, burning, tingling, itching, tightness), counted inflammatory and non‑inflammatory lesions on the back (papules, pustules, nodules, open and closed comedones), assessed severity using Comprehensive Acne Severity Scale (CASS) and Truncal Acne Severity Scale (TRASS), scored post‑inflammatory marks (Post-Inflammatory Hyperpigmentation PIH, Post-Inflammatory Erythema PIE) on a 10-point scale, and took standardized back photographs. The Cardiff Acne Disability Index (CADI) and self‑assessment questionnaires (efficacy and cosmeticity) were completed at each visit. Compliance was checked by verifying the daily log and remaining or returned investigational product at each visit and adverse events were recorded at each visit.

Data from 34 subjects aged between 14 to 33 years old were analyzed in this study. 

After 56 days of twice‑daily use, the anti-blemish soothing spray induced a progressive and significant improvement in PIH, PIE and global acne severity (CASS and TRASS), with mean reductions up to -38.5% (p<0.001, Wilcoxon test) for CASS and -21.8% (p<0.001, Wilcoxon test) for TRASS at D56.

All acne lesions (retentional and inflammatory lesions, comedones, papules and pustules) decreased significantly from D7 to D56; at D56, reductions ranged from about -55% to -100%, with the largest decreases in open comedones (-100%; p<0.001, Wilcoxon test) and total lesions (-70%; p<0.001, Wilcoxon test). 

Visual Analogue Scale (VAS) scores showed a progressive reduction in perceived severity, marks and discomfort, with the sum of scores decreasing by -33.1% (p<0.001, Wilcoxon test) at D56. CADI indicated a marked improvement in quality of life, with total‑score reduction up to -48.1% (p<0.001, Wilcoxon test) at D56. After 56 days of product use, most subjects (>60%) agreed or somewhat agreed with all benefit-related statements, with particularly high agreement (>73.5% to 97.1%; mean value calculation) for reduction of imperfections, soothing effects, improved quality of life, and cosmetic properties of the product.

Cutaneous tolerance was rated good, with no significant worsening of any objective or subjective sign over time.

The product is easy to apply and distributed evenly over all areas of the body, even the hard-to-reach ones for respectively 97% and 79% of the subjects. 

After 56 days of twice-daily use, the anti-blemish soothing spray demonstrated clear efficacy on mild to moderate truncal acne, with progressive improvement in post‑inflammatory marks, global severity and most lesion types. The product showed very good tolerance and strong subject‑reported satisfaction and improvement in quality of life, supporting its use as a well‑tolerated and effective option for managing mild to moderate truncal acne.