Acne is a common disease worldwide, predominantly occurring in teenagers. New treatment methods are of interest to circumvent prevalent challenges like antibiotic resistance and local adverse effects. Cold atmospheric plasma (CAP) is a well-tolerated, physical treatment that is well established in the treatment of chronic wounds since it provides bactericidal and wound healing properties. Our aim was to evaluate whether CAP is an effective add-on therapy for patients with mild acne papulopustulosa in a randomised controlled, double-blind pilot study to reduce total inflammatory lesion count (TILC), including papules and pustules, and improve Investigator Global Acne (IGA) score. The secondary endpoints were changes of sebum levels and Cutibacterium acnes colonization via total porphyrin count (TPC), improvement of quality of life via Acne Quality of Life questionnaire (Acne-QOL), and adverse events (AE). Forty patients were randomised into two groups of 20 patients. The endpoint of the treatment was at six weeks, and follow-up at week ten. Both groups applied daily adapalene cream 0.1% and received weekly skin-cleansing by a physician. One half received weekly facial CAP-treatments with a CAP-device, while the other half received weekly placebo-device application. TILC, IGA, sebumetry, TPC, and AE were assessed at baseline, endpoint, and follow-up. Acne-QOL was assessed at baseline and endpoint. From baseline to endpoint, TILC and IGA mean values showed greater improvement in the verum group compared to the control group (p = 0.07 and p < 0.001, respectively). Comparing baseline and follow-up, a stronger improvement was observed only for IGA (p = 0.006), but not for TILC (p = 0.408).** Also, sebum and TPC levels, as well as Acne-QOL, decreased more in the verum group during treatment. AE cases were less frequent in the in verum group, with no serious AE occurring in general (all p< 0.005). CAP proved to be an efficient and well-tolerated add-on therapy for mild acne papulopustulosa by improving all endpoint outcomes better in verum than in control. Studies with longer treatment periods and greater cohorts are needed to further elucidate the impact of CAP on acne.

The dataset in the folder "Raw_images_files_of_measurements_Dryad" consists of files of 40 participants resulting from their visits during the interventional trial from baseline, post-treatment at week 6, until follow-up at week 10.

The file data includes screen-photographs to document measurements during visits of:

-Sebumetry measurements (“Sebumeter-SM 815” by Courage+Khazaka electronic GmbH ^®, Germany) consisting of 5 measurement areas (4 in one measurement graph and the fifth one on the next image due to software settings) from the mentalis region, right cheek, right forehead, left forehead, left cheek

-Fluorescence signaling camera images (“Visiopor PP 34“ by Courage+Khazaka electronic GmbH ^®, Germany) consisting of 5 measurement areas from the mentalis region, right cheek, right forehead, left forehead, left cheek

The CAP_acne.html file was created and exported with the software "R Markdown"^®