Introduction: Folliculitis is a painful infection and inflammation of the hair follicles, mostly caused by bacterial, fungal, or, more rarely, viral infections. Turpentine derivatives have been used traditionally to treat various skin infections and could thus also be effective in treating folliculitis. We carried out an open, prospective, randomized, placebo- and comparator-controlled multicenter trial to evaluate the efficacy and safety of an ointment containing pine turpentine oil, larch turpentine, and eucalyptus oil in the treatment of acute folliculitis. Methods: Seventy outpatients with acute folliculitis were treated with the turpentine ointment, a comparator (povidone iodine solution), or a placebo (Vaseline) for 7 days. Photographs of the affected skin areas were taken by the physicians at four visits and by the patients on a daily basis. Photographs were evaluated by blinded observers. Primary efficacy endpoint was the change in total hair follicle lesion counts. Secondary endpoints included the evolution of the lesion counts in the course of the study, responder rate (improvement of follicle lesions by at least one count), and the patient’s global assessment. Safety endpoints were the tolerability of the treatments and adverse event recording. Results: A decrease of follicle lesions counts was detected for both active treatments but not for placebo, but the differences among groups were not statistically significant. As for the secondary endpoints, the ointment showed statistically significant superiority over placebo for the evolution of the lesions during the course of the study (p = 0.017), the responder rate (p = 0.032), and the subjective efficacy assessment by patients (p = 0.029). All treatments were equally well tolerated, with a similar number of treatment-emergent adverse events. Conclusion: The turpentine ointment is an effective and safe option for the treatment of folliculitis.

Five million hair follicles are formed during human embryogenesis, with only less than 150,000 of them being located on the scalp. Hair follicles extend from the skin surface to the dermis or subcutaneous tissue and connect directly with the sebaceous gland [1], creating a moist, perfused, and relatively well UV-protected tissue column with a pH favorable to microbial growth [2]. Folliculitis, a painful infection and inflammation of hair follicles characterized by perifollicular papules or pustules on an erythematous base, is generally caused by bacterial, fungal, or, more rarely, viral infections, as well as chemicals or physical injury [3], and may develop anywhere on skin areas subject to rubbing, occlusion, and sweating, such as the neck, face, axillae, and buttocks [4]. Folliculitis is most commonly caused by Staphylococcus aureus and other Staphylococcus spp., streptococci, but Pseudomonas aeruginosa as well as some yeasts (Candida spp., Malassezia spp.) are also potential etiological agents. The diagnostic workup is mainly based on clinical signs. Microbiological identification of the causal agents is usually not required unless treatment failure is observed [3]. An extensive microbiological testing is indicated only in patients with deep infections of the soft tissues [5].

The prevalence and incidence of folliculitis is unknown [6]. Superficial folliculitis is usually self-limiting and resolves within a few days [6], but topical antibiotics or antiseptics are commonly used to reduce pain and itching and avoid progression of the superficial folliculitis to boils or furuncles. Recommended topical antiseptics include polyhexanide, povidone iodine, octenidine, and chlorhexidine [5]. Topical antibiotics (e.g., fucidin, mupirocin, clindamycin) are rarely used [5]. Extensive information is available on the efficacy and safety of topical antiseptic and antibacterial products used for the treatment of skin conditions, yet only very few placebo- or comparator-controlled clinical trials have so far been performed to assess their efficacy and safety. A Cochrane review, for instance, analyzed 18 randomized, controlled trials carried out with 30 different products, including 1,300 participants, but its authors could retrieve useful data only for six topical treatments [4].

Pull ointments containing ammonium bitumino-sulfonate or turpentine derivatives have been used traditionally to treat various skin infections [7]. Turpentine and volatile oils (e.g., turpentine oil, eucalyptus oil) have been ascribed antiseptic and skin perfusion-enhancing properties. Topical turpentine oil has been shown to exert disinfectant, analgesic, antiparasitic [8], and antimicrobial activities [9, 10], and antimicrobial properties have also been reported for eucalyptus oil [9, 11]. These substances are included in a marketed pull ointment (ilon® Salbe classic) that contains a lipophilic mixture of 7.2% pine turpentine oil, 5.4% larch turpentine, and 1.2% eucalyptus oil as active substances. This ointment is indicated for the treatment of mild, localized, purulent inflammations of the skin, such as nodules, inflamed hair follicles, and sweat gland inflammations. A double-blind, randomized clinical trial in 116 outpatients with skin abscesses showed that the ointment is an effective and safe option for the treatment of bacterial skin infections [12]. The data, however, were derived from a clinical trial carried out with a slightly different galenical formulation than the currently marketed one, and the design used only subjective endpoints. Therefore, we decided to carry out a pilot trial using objective endpoints to evaluate the efficacy and safety of the presently marketed galenical formulation in the treatment of acute folliculitis.

Study Design

This was a prospective, open-label, randomized, placebo- and comparator-controlled, multicenter trial carried out at 7 centers in Germany from July 2017 until March 2018. The open-label design was chosen because the characteristic odor of the verum and the use of a liquid comparator precluded blinding. A double-dummy design was not a viable option, as it would have made the study too cumbersome for the participants. To partly compensate for the open study design, clinical assessments were based on photos of the affected skin areas and evaluated by independent blinded observers.

Patients

Male or female, 18- to 80-year-old Caucasian outpatients diagnosed with acute folliculitis were eligible for this trial. To participate, patients had to be able to understand the objective of the trial and take pictures of the affected skin area using a smartphone.

Patients presenting skin lesions or skin diseases other than acute folliculitis, undergoing any treatment with epidermal growth factor receptor inhibitors or any systemic or topical immunosuppressive therapy within 3 weeks prior to randomization, suffering from hyperthyroidism or congenital or acquired immunodeficiency, or having participated in any other study within 30 days prior to randomization, were not included in the trial. Contraindications to the use, known allergy or intolerance to any component of the study medications, history of drug, alcohol, or chemical abuse were additional exclusion criteria. Pregnant and lactating women were also not allowed to enter the trial.

Topical use of dermatological (medicinal or cosmetic) products on the affected skin areas or any systemic antibiotic therapy were not allowed during the whole trial period. Other ongoing systemic or topical therapies, on the other hand, were allowed as far as they did not interfere with the trial objectives. Subjects had to avoid UV radiation and maintain constant washing habits during the trial.

Sample Size and Randomization

No data were available on the effect size of the verum or any standard therapy (a comparator) in this indication, and no reliable information was available to allow a sample size estimation against placebo. Therefore, this study was designed to get information about the extent of efficacy that can be expected from both verum and comparator. We estimated that at least 20 evaluable patients in each study arm were needed to obtain scientifically relevant results. To account for likely dropouts, we planned to include 75 patients to ensure at least 60 evaluable patients.

Eligible subjects who met all inclusion and exclusion criteria were randomly assigned to one of three treatment arms in a 1:1:1 ratio to receive either the ointment containing natural resins and oils (verum), a disinfectant (comparator), or placebo for 7 days. It was planned to include 25 patients in each treatment arm. Randomization was carried out using a computer-generated sequence.

Investigational Medicinal Products

The verum was a marketed turpentine ointment (ilon® Salbe classic, Cesra Arzneimittel GmbH & Co. KG; Germany) containing a lipophilic mixture of 7.2% pine turpentine oil derived from Pinus pinaster AIT., 5.4% larch turpentine extracted from Larix decidua MILL., and 1.2% eucalyptus oil extracted from Eucalyptus globulus LABILL., as active pharmaceutical ingredients. All were analyzed according to the European (Ph. Eur.) or Swiss pharmacopeia (Ph. Helv.). Pine turpentine oil consists mainly of monoterpenes such as α- and β-pinene (approx. 95%) [13]. Larch turpentine is a resin of the larch tree and consists of resin acids (up to 65%; mainly larixyl acetate) and essential oils [14], whereas eucalyptus oil contains mainly 1,8-cineole (≥80%) [15]. Essential volatile oils from rosemary (Salvia rosmarinus Spenn.), thyme (Thymus vulgaris L.), and thymol are included as excipients. The ointment basis consists of Vaseline (72%) and beeswax, chlorophyll paste, stearin, oleic acid, and polysorbate 20. The diffusion of the active substances in the skin is considered to be improved by the ointment’s occlusive effect that leads to an increase in moisture of the stratum corneum [16]. The comparator was a liquid disinfectant containing 100 mg povidone iodine per milliliter (Polysept®, Dermapharm AG, Germany). A marketed Vaseline ointment (Vaselin Salbe LAW 100%, Abanta Pharma GmbH, Germany) was used as placebo. Two centimeters of ointment cords of the verum or placebo or 5 mL of the comparator were spread twice daily on the area to be treated.

Interventions

The trial lasted 7 days and comprised one visit at the start (day 0), a second on day 2 or 3, a third on day 4 or 5, and a last visit on day 7. On the visit days, the trial medication was applied once during the visit by the study site staff, otherwise autonomously by the subject, for a total of 2 applications daily. At the start of therapy, the diseased skin area (5 × 5 cm) was delimited by the investigators with a waterproof skin marker. To document changes in the number of infected follicles over time, pictures of the folliculitis lesions were taken by the investigators during the four visits and by the patient daily using a smartphone. All pictures were collected and analyzed centrally by two independent and blinded observers. If the evaluations by the two observers differed and no agreement could be reached, a third, experienced dermatologist would take the final decision.

The patients were also asked to complete a diary in which they had to document adherence to the treatment and provide a global assessment of efficacy and tolerability. Compliance was controlled at each visit by a check of the daily entries in the diary and by weighing the returned ointment tubes and comparator bottles. Additional concurrent medications, adverse effects, and overall tolerability were recorded at each visit.

Endpoints

The primary efficacy endpoint was the change in total hair follicle lesion counts from visit 1 (day 0) to study completion (day 7) using the pictures taken by the physicians during the first and the last visit. Secondary endpoints included the evolution of the number of lesions based on the daily pictures taken by the patients, the responder rate (defined as a reduction by at least one count in diseased follicles at the end of the study), and the patient’s global assessment of overall efficacy and impact on pain on the basis of a Visual Analog Scale (VAS; 0: very bad, 10: very good). Tolerability was assessed by investigators and patients also using a VAS (0: very bad, 10: very good). Frequency and severity of adverse events (AE) occurring during the trial were recorded to assess treatment safety.

Statistics

All statistical analyses were carried out using a modified intention-to-treat (ITT) population that included all randomized subjects who received at least one dose of treatment and had evaluable pictures taken at days 0 and 7. The follicle counts were analyzed unweighted (i.e., raw counts) and after a weighted transformation. Weighted data were computed by adding the number of purulent follicles multiplied by 3, the number of inflamed follicles multiplied by 2, and the raw number of healing follicles.

Age is presented using descriptive statistics (n, mean, standard deviation [SD], interquartile range), and gender by the count and percentage of subjects in each category. Folliculitis localization and physician’s global assessment of disease severity are summarized using the number and proportion of subjects in each treatment group and category. For all categorical variables, the counts and percentages of each category were calculated using non-missing data only.

Analysis of variance (ANOVA) adjusted for baseline values was used for all inferential analyses with continuous data, unless non-normality of data did not allow it, and χ2 or Fisher’s exact test, as appropriate, for frequency data. A Wilcoxon rank sum test was used to analyze the subjective efficacy evaluation by the patients.

All statistical tests were two-tailed, and statistical significance was set to p = 0.05. All descriptive and inferential statistical analyses were performed using SAS statistical software (SAS Institute, Cary, NC, USA, version 9.4).

Patients’ Disposition

The patients’ disposition and flow are presented in Figure 1. Seventy subjects agreed to sign the informed consent and were included in the trial. The treatment arms were comparable with regards to age and gender (Table 1). More than 70% of the patients were 18–39 years old, with a slightly higher (58%), but statistically not significantly different, share of females in the comparator group. The localization of the folliculitis lesions was similar in the three groups, but in the comparator group, the lesions were more broadly distributed over the body surface of the participants (46%). Overall, compliance to the treatment was good in all groups.

Fig. 1.

Patients’ disposition.

Fig. 1.

Patients’ disposition.

Close modal
Table 1.

Patients’ demographics

ParameterVerum (n = 21)Placebo (n = 25)Comparator (n = 24)Total (n = 70)
Age, years, mean (SD); Q1–Q3 33.5 (13.94); 24–38 36.3 (16.32); 26–45 39.8 (14.88); 29–51.5 36.7 (15.14); 26–48 
Age classes, n (%) 
 18–29 12 (57.1) 15 (60.0) 7 (29.2) 34 (48.6) 
 30–39 5 (23.8) 3 (12.0) 8 (33.3) 16 (22.9) 
 40+ 4 (19.1) 7 (28.0) 9 (35.5) 20 (28.5) 
Gender, n (%) 
 Male 10 (47.6) 14 (56.0) 10 (41.7) 34 (48.6) 
 Female 11 (52.4) 11 (44.0) 14 (58.3) 36 (51.4) 
Localization of lesions, n (%) 
 Abdomen 2 (8.0) 2 (2.9) 
 Back 4 (19.0) 5 (20.0) 5 (20.8) 14 (20.0) 
 Beard 2 (9.5) 2 (8.0) 2 (8.3) 6 (8.6) 
 Breast 3 (14.3) 3 (12.0) 2 (8.3) 8 (11.4) 
 Forehead 1 (4.8) 1 (1.4) 
 Genital area 5 (23.8) 1 (4.0) 1 (4.2) 7 (10.0) 
 Neck 2 (8.0) 2 (8.3) 4 (5.7) 
 Thigh 3 (14.3) 4 (16.0) 1 (4.2) 8 (11.4) 
 Other 3 (14.3) 6 (24.0) 11 (45.9) 20 (28.6) 
ParameterVerum (n = 21)Placebo (n = 25)Comparator (n = 24)Total (n = 70)
Age, years, mean (SD); Q1–Q3 33.5 (13.94); 24–38 36.3 (16.32); 26–45 39.8 (14.88); 29–51.5 36.7 (15.14); 26–48 
Age classes, n (%) 
 18–29 12 (57.1) 15 (60.0) 7 (29.2) 34 (48.6) 
 30–39 5 (23.8) 3 (12.0) 8 (33.3) 16 (22.9) 
 40+ 4 (19.1) 7 (28.0) 9 (35.5) 20 (28.5) 
Gender, n (%) 
 Male 10 (47.6) 14 (56.0) 10 (41.7) 34 (48.6) 
 Female 11 (52.4) 11 (44.0) 14 (58.3) 36 (51.4) 
Localization of lesions, n (%) 
 Abdomen 2 (8.0) 2 (2.9) 
 Back 4 (19.0) 5 (20.0) 5 (20.8) 14 (20.0) 
 Beard 2 (9.5) 2 (8.0) 2 (8.3) 6 (8.6) 
 Breast 3 (14.3) 3 (12.0) 2 (8.3) 8 (11.4) 
 Forehead 1 (4.8) 1 (1.4) 
 Genital area 5 (23.8) 1 (4.0) 1 (4.2) 7 (10.0) 
 Neck 2 (8.0) 2 (8.3) 4 (5.7) 
 Thigh 3 (14.3) 4 (16.0) 1 (4.2) 8 (11.4) 
 Other 3 (14.3) 6 (24.0) 11 (45.9) 20 (28.6) 

SD, standard deviation; Q1–Q3, interquartile range (H-spread).

Efficacy Evaluation

Primary Endpoint

Photographs from 22 patients were not available, thus only 48 subjects were evaluable at day 0 and day 7. The total follicle lesion counts at day 0 to day 7 and the corresponding changes are presented in Table 2. The mean counts in the verum decreased by 0.9 and in the comparator groups by 1.3. They increased by 0.4 under placebo treatment. The differences were not statistically significant (ANOVA adjusted for day 0 values).

Table 2.

Follicle lesion counts and their changes (as means [standard deviation], interquartile ranges) from day 0 to day 7 (final visit) based on the pictures taken by the investigators

Verum (n = 16)Placebo (n = 17)Comparator (n = 15)
Unweighted 
 Day 0 5.1 (5.39), 1.5–6.0 4.3 (3.29), 1.0–7.0 5.2 (6.47) 1.0–6.0 
 Day 7 4.2 (4.18), 1.0–6.0 4.7 (4.10), 2.0–7.0 3.9 (2.64), 1.0–6.0 
 Change −0.9 (5.25), −3.0–0.0 0.4 (3.83), 0.0–2.0 −1.3 (5.86), −3.0–2.0 
Weighted* 
 Day 0 10.6 (10.95), 3.5–12.5 9.2 (7.67), 3.0–14.0 11.4 (13.93), 2.0–12.0 
 Day 7 8.0 (8.41), 1.0–12.5 9.1 (7.83), 4.0–14.0 7.2 (5.25), 1.0–10.0 
 Change −2.6 (10.92), −7.0–0.0 −0.1 (8.41), −1.0–3.0 −4.2 (11.75), −6.0–4.0 
Verum (n = 16)Placebo (n = 17)Comparator (n = 15)
Unweighted 
 Day 0 5.1 (5.39), 1.5–6.0 4.3 (3.29), 1.0–7.0 5.2 (6.47) 1.0–6.0 
 Day 7 4.2 (4.18), 1.0–6.0 4.7 (4.10), 2.0–7.0 3.9 (2.64), 1.0–6.0 
 Change −0.9 (5.25), −3.0–0.0 0.4 (3.83), 0.0–2.0 −1.3 (5.86), −3.0–2.0 
Weighted* 
 Day 0 10.6 (10.95), 3.5–12.5 9.2 (7.67), 3.0–14.0 11.4 (13.93), 2.0–12.0 
 Day 7 8.0 (8.41), 1.0–12.5 9.1 (7.83), 4.0–14.0 7.2 (5.25), 1.0–10.0 
 Change −2.6 (10.92), −7.0–0.0 −0.1 (8.41), −1.0–3.0 −4.2 (11.75), −6.0–4.0 

Modified ITT population.

*Weighted count was defined as the sum of the number of purulent follicles (yellow color, weight factor 3) plus number of inflamed follicles (red color, weight factor 2) plus raw number of healing follicles (brown color, weight factor 1).

Secondary Endpoints

The differences in total follicle lesion counts among groups were more marked compared to placebo when the weighted counts were used (Table 2), but they were not statistically significant (ANOVA adjusted for day 0 values). During the course of the study, the mean counts (as assessed by daily pictures taken by the patients) decreased in both active treatment groups and remained constant for placebo until day 5; thereafter, they increased slightly for the comparator and decreased for verum and placebo (Fig. 2). A significant treatment-by-time interaction among groups, with a statistically significant difference between verum and placebo was observed (p = 0.017, repeated measures ANOVA).

Fig. 2.

Course of total follicle lesion counts (mean and standard error of mean) from day 0 to day 7 based on the evaluation of the daily pictures taken by the patients. All 70 patients were included: ISC = verum (n = 21), placebo (n = 25), and comparator (n = 24). A significant treatment by time interaction among groups, with a statistically significant difference between verum and placebo was observed (p = 0.017, repeated measures ANOVA).

Fig. 2.

Course of total follicle lesion counts (mean and standard error of mean) from day 0 to day 7 based on the evaluation of the daily pictures taken by the patients. All 70 patients were included: ISC = verum (n = 21), placebo (n = 25), and comparator (n = 24). A significant treatment by time interaction among groups, with a statistically significant difference between verum and placebo was observed (p = 0.017, repeated measures ANOVA).

Close modal

The responder rate, defined as the share of patients with a reduction by at least one count in diseased follicles at the end of the study, was highest under verum and statistically significantly superior to placebo (Table 3; p = 0.032, Fisher’s exact test). The subjective efficacy evaluation by the patients (Table 4), based on the entries in the patient’s diaries, indicated that verum was statistically significantly better as compared to placebo with regards to overall efficacy (p = 0.029, Wilcoxon rank sum statistic). Similar results were obtained for the impact on pain, although the active treatments were not statistically significantly different from placebo (Table 4).

Table 3.

Responder rate, defined as the number of patients with a reduction by at least one diseased follicle (N [%]), from day 0 to day 7 (modified ITT population)

Verum (n = 16)Placebo (n = 17)Comparator (n = 15)
Not improved 7 (43.75) 14 (82.35) 10 (66.67) 
Improved 9 (56.25) 3 (17.65) 5 (33.33) 
% difference verum–placebo, mean (95% CI)  −38.6 (68.92;–8.28)  
% difference verum–comparator, mean (95% CI)   −22.92 (−56.97;11.14) 
Verum (n = 16)Placebo (n = 17)Comparator (n = 15)
Not improved 7 (43.75) 14 (82.35) 10 (66.67) 
Improved 9 (56.25) 3 (17.65) 5 (33.33) 
% difference verum–placebo, mean (95% CI)  −38.6 (68.92;–8.28)  
% difference verum–comparator, mean (95% CI)   −22.92 (−56.97;11.14) 

Verum was statistically significantly superior to placebo (p = 0.032, Fisher’s exact test).

Table 4.

Subjective efficacy evaluation of the study medication (rating scale: 0, very bad; 10, very good) by the patients (patient’s diaries, all 70 patients)

VerumPlaceboComparatorp value (Wilcoxon rank sum)
Overall efficacy 
N 21 25 23 Verum versus placebo: 0.029 
 Mean (SD) 5.8 (2.98) 3.7 (2.99) 6.3 (2.77) Verum versus comparator: 0.589 
 IQR 3.0–8.0 1.0–5.0 4.0–9.0  
Impact on pain 
N 18 21 21 Verum versus placebo: 0.077 
 Mean (SD) 5.9 (2.70) 4.0 (3.11) 5.9 (3.24) Verum versus comparator: 0.966 
 IQR 5.0–8.0 1.0–6.0 3.0–9.0  
VerumPlaceboComparatorp value (Wilcoxon rank sum)
Overall efficacy 
N 21 25 23 Verum versus placebo: 0.029 
 Mean (SD) 5.8 (2.98) 3.7 (2.99) 6.3 (2.77) Verum versus comparator: 0.589 
 IQR 3.0–8.0 1.0–5.0 4.0–9.0  
Impact on pain 
N 18 21 21 Verum versus placebo: 0.077 
 Mean (SD) 5.9 (2.70) 4.0 (3.11) 5.9 (3.24) Verum versus comparator: 0.966 
 IQR 5.0–8.0 1.0–6.0 3.0–9.0  

SD, standard deviation; IQR, interquartile range.

Safety Evaluation

All treatments, as assessed daily by the patients, were well tolerated throughout the whole trial duration and confirmed by the investigators’ evaluations at the final visit. No statistically significant differences in tolerability were observed across groups (data not shown).

Seven patients (10%) reported 8 adverse events (AEs). No AE was assessed as serious. In the verum group, 3 AEs (diarrhea, rash, and itching); in the placebo group, 2 AEs (itching and erythema); and in the comparator group, 3 AEs (contact dermatitis, two times reddening) were reported.

This pilot study has shown that the ointment containing pine turpentine oil, larch turpentine, and eucalyptus oil, reduces the number of follicle lesions and contributes to the healing of folliculitis. Folliculitis improvement, assessed as the reduction in the number of diseased follicles from day 0 to day 7, was observed in both active treatment groups. More marked reductions were seen when weighted counts were used, but the differences among treatments were not statistically significant in either analysis, probably because of the large variance of the data and the small sample size. Placebo, on the other hand, did not favor healing (Table 2).

For the secondary endpoints, on the other hand, statistically significant differences between verum and placebo could be observed. During the course of the study, the mean counts of diseased follicles decreased most pronouncedly with verum (Fig. 2). Also, more patients showed an improvement of diseased follicles by at least one lesion count in the verum group (Table 3). The best scores in the patients’ subjective evaluation of efficacy at the end of the study were also observed in the verum group.

These results agree with those reported by Fuchs-Algrim et al. [12] who investigated the effects of the ointment in patients with skin abscesses. The authors showed a better improvement in the verum compared to the placebo group with regards to the patient’s discomfort sum score and a higher treatment success rate after verum, with complete healing in 67% of the patients receiving verum versus 46% in the placebo group, a statistically significant difference (p = 0.037). They also reported a positive trend toward a larger decrease in the abscess sizes in the verum than in the placebo group.

Healing of surgical wounds after treatment with a pine resin salve containing turpentine has also been reported by Sipponen et al. [17], with a healing rate of 100%. The patient population included in the Sipponen et al. [17] trial is obviously not comparable to that of our investigation, but nevertheless, it supports the efficacy of turpentine-containing products in healing skin conditions.

This study has some limitations. The subjective assessments by patients may have been biased by the open study design. On the other hand, the clinical assessments with respect to the follicle lesion counts have been performed by blinded observers using photographs of the affected skin areas.

No published or unpublished data were available to allow a reliable sample size estimation. The decision of carrying out a pilot trial to assess the effect size of the verum compared to the standard therapy (the comparator) or placebo increased the risk of not achieving any statistical significance. In addition, we cannot exclude that microorganisms resistant to the topical treatments used contributed to the variance in the individual treatment outcomes. Finally, we limited our observations to 7 days and having expanded them to 10 or more days could have helped differentiating the efficacy of the active treatments versus placebo.

This notwithstanding, this pilot study has shown that the ointment used is effective in treating mild bacterial folliculitis. It is also cost-effective, well tolerated, and safe.

We thank Orlando Petrini, PD, PhD (Breganzona, Switzerland), for critically reviewing the manuscript.

The study protocol was reviewed and approved by the Ethics Committee of the State Medical Association of Rhineland-Palatinate and the German Federal Institute for Drugs and Medical Devices (BfArM, approval number 4041978). All participants provided written informed consent before entering the trial. The trial was registered at EudraCT with the number 2016-005105-39 and at the German Registry of Clinical Trials (Deutsches Register Klinischer Studien: DRKS) with the number DRKS00012746.

Christian Zimmermann and Nils Günnewich are employees of Cesra Arzneimittel GmbH. Hilde Huber and Britta Wallmen have received compensation for the trial organization, monitoring, and analysis. The other authors have no conflicts of interest to declare.

This study was supported by Cesra Arzneimittel GmbH & Co. KG.

Christian Zimmermann designed and supervised the study. Rainer Görne was the coordinating investigator and medical advisor of the study. Hilde Huber and Britta Wallmen managed the project. Hilde Huber prepared the final study report. Nils Günnewich and Christian Zimmermann prepared this manuscript. The members of the Folliculitis Study Group carried out the clinical investigations. All authors reviewed the manuscript and gave guidance for the preparation.

Additional Information

On behalf of the Folliculitis Study Group, membership is provided as online supplementary material (for all online suppl. material, see https://doi.org/10.1159/000535711).

The data that support the findings of this study are not publicly available due to company secret reasons but are available from the corresponding author upon reasonable request.

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