Novel Global Assessment of Truncal Acne Severity Developed

Acne on a person's face
Acne on a person’s face
As no designated scale for the measurement of truncal acne severity exists, investigators developed an easy-to-use clinical tool that uses a global approach.

The feasibility and efficacy of the Truncal Acne Severity Scale (TRASS) to grade the clinical signs of truncal acne found support in study data published in the Journal of the European Academy of Dermatology and Venereology. Developed by investigators, TRASS showed high correlation with other assessments of acne severity and displayed internal consistency across subscales. The investigators believe these results support the use of this novel tool in clinical practice.

No designated scale for the measurement of truncal acne severity exists. To inform this gap, investigators developed TRASS, an easy-to-use clinical tool that uses a global approach. Briefly, TRASS is based on 3 subscores which sum to a number between 0 and 19, with higher numbers indicating greater severity. Scale 1 captures disease history, including acne duration, family history, and past treatment exposure; scale 2 rates acne severity using the number of nodules and scars on the trunk and the presence of acne on the face; and scale 3 assesses the effect of truncal acne on patient’s self-reported quality of life. To test the feasibility of TRASS, a panel of dermatology experts used photographs of 47 patients attending participating clinics in France. Patient acne severity was assessed using existing diagnostic means and classified as “low grade” or “high grade.” TRASS was then applied to each patient photograph; the agreement between TRASS and initial clinical assessment was tested using regression models. Correlation analyses were performed to assess the internal agreement between TRASS subscales.

TRASS accurately identified most patients with clinician-designated “severe” acne. When the median TRASS value was used as the cut-off point, TRASS correctly distinguished low-grade from high-grade acne with a very low error rate (6.6%). When the 75th percentile of TRASS was used to designate severe acne, the error rate increased slightly but remained low (10.4%). Further modeling found that the subscales capturing family history, facial acne, and quality of life were not necessary to discriminate low- from high-grade acne. However, the most affected quartile of patients were better identified when family history and quality of life scores were incorporated.

Significant correlations were observed between systemic treatment exposure and scores measuring scars (P =.0025) and nodules (P =.01988). Similarly, acne location was significantly associated with patient-reported quality of life (P =.0095). An inverse correlation was observed between acne duration and the extent of acne lesions on the trunk, with longer duration often associated with lesser severity.

Study limitations include the small sample size; replication in a larger cohort is necessary to confirm the efficacy of TRASS the researchers suggest.

“TRASS is the first global, patient-centered approach to evaluate truncal acne by scoring the importance of each factor independently from its clinical severity,” investigators wrote. “TRASS may allow the practitioner to choose and validate the most suitable therapy together with the patient in order to treat his or her truncal acne successfully and to limit treatment failure.”

Disclosure: This research was supported by Galderma International, France. Please see the original reference for a full list of disclosures


Auffret N, Nguyen JM, Leccia MT, Claudel JP, Dréno B. TRASS: a global approach to assess the severity of truncal acne. J Eur Acad Dermatol Venereol. Published online February 16, 2022. doi:10.1111/jdv.18009