Acne vulgaris is the most common dermatopathy worldwide, with a prevalence of 70–87% [1]. Moreover, acne vulgaris generally occurs among adolescents and young adults [2]. This facial-centered skin disease can negatively affect the psychosocial well-being of the affected individuals. Özkesici Kurt [3] have reported low self-regard in more than one-fifth of the patients with acne, low body satisfaction in more than one-third, and severe quality of life (QoL) impairment in more than two-thirds of patients. Notably, impaired self-regard was more noticeable in adolescents than in adults. According to Dang’s [4] survey targeting 958 high school girls, 83.7% of them had acne. Moreover, those with acne had a significantly higher stress score (p < 0.01) than the girls without acne. When examining the causes of stress (from the highest to the lowest impact), appearance is the most contributing factor, followed by study and grade, and then, family and friends. Among various skin diseases, acne has one of the highest incidence and recurrence rates. Moreover, acne is a chronic disease that is difficult to treat [5]. Thus, the other treatment options for acne needs to be examined.

Sebaceous gland hyperplasia due to increased androgen levels is the key pathogenesis of acne. Other contributing factors include the colonization and growth of Propionibacterium acnes enclosed by the sebaceous gland, abnormal follicular hyperkeratinization, and inflammatory reactions [6]. Locally applied medications are recommended as standard treatment. Topical applications may cause erythema, dryness, and irritation. Therefore, oral treatment is often recommended for inflammatory acne, with antibiotics and isotretinoin being the most commonly prescribed drugs [7]. Both oral and topically applied antibiotic treatments can increase the resistance of P. acnes, resulting in a poor therapeutic response over time [8]. Isotretinoin is most often used to reduce comedogenesis by inhibiting sebum production, but side effects, including dryness of the skin and mucous membrane as well as lipid metabolism disorders, are common [9]. Furthermore, isotretinoin can lead to fetal abnormalities if used by pregnant women, so its use is limited [10].

Most acne treatment studies in the field of Oriental medicine have focused on ingested herbal medicines or externally applied medicines. Studies reporting ingested medicines include Lim et al.'s [11] study demonstrating the effect of Chungsangbangpungtang on acne, Lee and Hong’s [12] research investigating Bojoongikki-tang, and Tak et al.’s [13] investigation on the effect of Sasang constitutional prescription (Yangkyuksanhwa-tang and Yangdokbackho-tang) and Microneedle Therapy System (MTS) treatment in 81 patients with acne vulgaris. Contrarily, for studies on the externally applied treatments, Zhang et al. [14] have conducted a randomized controlled trial (RCT) comparing the effectiveness between the modified Qufeng Runmian powder (MQFRMP) and a placebo, Baek et al. [15] examined the Sophorae Radix-skin lotion, Du et al. [16] performed an RCT comparing the effect of a 5% Herba Houttuyniae extract solution with that of distilled water, and Sung et al. [17] have conducted a systematic review and meta-analysis on the effects of externally applied herbal medicines for treating acne vulgaris.

Existing acupuncture treatment studies have often focused on treating acne scars [18-20], and information from Korean medicine studies showing that acupuncture can help to treat inflammatory acne vulgaris is lacking. To provide evidence for clinical application, we analyzed the data from RCTs on acupuncture treatment for inflammatory acne to determine its effectiveness.

1. Selection and exclusion criteria

The inclusion criteria were as follows: (1) studies involving patients diagnosed with acne vulgaris; and (2) RCTs on acupuncture treatment, irrespective of the stimulation method used (acupuncture, needling, acupressure), needle type, duration, and acupuncture points.

The exclusion criteria include (1) duplicate studies; (2) studies without full texts; (3) non-RCTs; (4) studies published in non-academic medical journals; (5) studies not mentioning acupuncture treatment; and (6) studies involving patients with acne scars only.

The literature review had no limitations in terms of the country of publication of the studies, language of the article, and patients’ sex, age or race.

2. Database and search methods

We searched EMBASE, PubMed, Cochrane Library, China National Knowledge Infrastructure (CNKI), Research Information Sharing Service, Oriental Medicine Advanced Searching Integrated System, and Korean studies Information Service System for relevant studies published from March 1, 2019, to January 27, 2024. The search terms included “acne*,” “Korean medicine,” “acupuncture” and “randomized controlled trial.” The following keywords were used for additional searches and adjusted for each database: (“Acne*”) AND (“Korean Medicine” OR “Traditional Medicine”) AND (“Acupuncture” OR “Needl*” OR “Acupoints” OR “Pharmacoacupuncture”).

1. Flowchart

As shown in Fig. 1, the titles and abstracts obtained from the initial retrieval were scanned, and duplicates were removed. The articles were screened and their full texts were reviewed according to the inclusion and exclusion guidelines. Finally, four studies were accepted for analysis.

Figure 1. Preferred Reporting Items for Systematic Reviews and Meta-Analyses flowchart. CNKI, China National Knowledge Infrastructure; RISS, Research Information Sharing Service; KISS, Korean studies Information Service System; OASIS, Oriental Medicine Advanced Searching Integrated System; RCT, randomized controlled trial.

2. Analysis

Four RCT studies, by Jiao et al. [21], Zhao [22], Gao et al. [23], and Pang et al. [24] were analyzed and summarized in Table 1.

Table 1 . Study analysis: acupuncture for inflammatory acne vulgaris.

First author (year)	Sample size	Intervention group (A)	Control group (B)	Outcome measurement	Results	Adverse effects
Jiao [21] (2022)	(A) n = 50 (B) n = 50	Acupuncture performed three times per week with 4 weeks	Sham acupuncture	1. Skindex-16 scale 2. Dermatology Life Quality Index 3. Skin lesions (TLC, ILC) 4. Visual analog scale (VAS) (IVAS, PVAS)	1–4. No difference (p > 0.05)	Not severe events
Zhao [22] (2019)	(A) n = 35 (B) n = 35	Percussopunctator prick (Maewha acupuncture) performed three times per week with 4 weeks	Vitamin A acid cream twice a day for 4 weeks	1. Effectiveness rate (ER) 2. Skin lesions	1. (A) 94.29%(B) 77.14% (p < 0.05) 2. A > B (p < 0.01)	Not severe events
Gao [23] (2022)	(A1) n = 30 (A2) n = 30 (A3) n = 30	Auricular bloodletting + auricular point sticking (A1) Once a week (A2) Twice a week (A3) Three times a week		1. GAGS 2. Skin lesions 3. Acne-QoL	1–3. No difference (p > 0.05)	Not severe events
Pang [24] (2021)	(A) n = 41 (B) n = 41	ZHU Lian inhibition type one acupuncture performed once every other day, totaling to 14 times	Danshentong capsules (1 g, three times per day) + 0.1% adapalene gel smear (once a day) for 4 weeks	1. GAGS 2. Acne-QoL 3. TNF-α, IL-6 4. ER	1–3. A > B (p < 0.05) 4. (A) 95.1%(B) 82.9% (p < 0.05)	Not mentioned

TLC, total lesion count; ILC, inflammatory lesion count; IVAS, itch assessment with the visual analog scale; PVAS, pain assessed by using a visual analog scale; GAGS, Global Acne Grading System; Acne-QoL, acne-specific quality of life; TNF-α, tumor necrosis factor-α; IL-6, interleukin-6..

1) Sample size

Overall, the data of 331 (127 male and 204 female) patients from four studies were analyzed.

In Jiao et al.’s [21] study, 100 patients with acne recruited from Guang'anmen Hospital were arbitrarily allocated to the experimental and control groups, with 50 patients each. Among the 100 patients, 80 were female and 20 were male. There was no remarkable difference in the baseline characteristics between the two groups.

In Zhao [22], 70 acne vulgaris patients from Zhuiyi Medical University Hospital were arbitrarily allocated to the experimental and comparison groups, with 35 patients each. Of the 70 patients, 38 were male and 32 were female, and no considerable difference was observed between the two groups.

In Gao et al. [23], 90 acne vulgaris patients from Hebei Chinese Medical University were randomly assigned to three experimental groups, with 30 patients each. During the experiment, the treatments for 11 cases, including two, four, and five cases in experimental groups 1, 2, and 3, respectively, were discontinued for personal reasons, and a total of 79 patients, including 28, 26, and 25 patients from experimental groups 1, 2, and 3, completed the treatments. Of these 79 patients, 21 were male and 58 were female, and no notable distinction was observed among the three groups.

In Pang et al. [24] that recruited patients from Guangxi Chinese Medicine University hospital, a total of 82 acne participants with spleen-stomach dampness-heat were arbitrarily allocated into the experimental and comparison groups, with 41 patients in each group. Of these 82 patients, 48 were male and 34 were female, and no considerable distinction was noted between the two groups.

2) Design and treatment method

In Jiao et al.’s [21] study, all participants were given 12 treatment sessions of acupuncture or sham acupuncture (30 minutes per session, three times per week for 4 weeks), and were then followed up for 24 weeks. Patients were recommended not to receive any other treatment options while participating in this study. In the experiment group, the participants received acupuncture treatment at the LI4 (Hegu), ST44 (Neiting), CV14 (Dazhui), and ST36 (Zusanli) acupoints. Acupuncturists used disposable needles (0.30 × 40 mm) and inserted the needles to a depth of 30–40 mm at an angle of 10–15° at the CV14 acupoint, and to a depth of 25–30 mm at the LI4, ST44, and ST36 acupoints. All needles were lightly manipulated three times to produce the de-qi response (a sensation of heaviness and numbness). In the control group, patients received sham acupuncture at the LI4, ST44, CV14, and ST36 acupoints (same as the experimental group) but the needles were inserted approximately 10 mm away from the original acupoints. Additionally, the sham needles were inserted perpendicularly to a depth of only 1–2 mm without any intervention for the de-qi response.

In Zhao’s [22] study, the experimental group received percussopunctator pricks (Maewha acupuncture) and a vitamin A acid cream was externally applied to the acne areas twice a day. The selected acupoints were CV14 (Dazhui), BL13 (Feishu), LI11 (Quchi), and SP10 (Xuehai), and at the areas with acne. After disinfecting the affected areas, the doctor held the needle vertically and pricked along the hand–foot yangming meridian for approximately 1 minutes (60–80 times/min). Both the experimental and control groups were given the vitamin A acid cream that should be applied for 4 weeks (1 treatment course).

Gao et al.’s [23] study enrolled 90 acne vulgaris patients who were assigned randomly to three experimental groups. The first, second, and third groups received treatment once, twice, and thrice a week, respectively. All experimental groups received a combination treatment of auricular bloodletting and auricular point pricking at the TF4 (Shenmen), CO14 (Fei), TG2P (Shenshangxian), and CO18 (Neifenmi) acupoints. After disinfecting the venous blood vessel of the auricular point, the acupuncturists pricked the point 1–3 times with a 0.7-mm needle to obtain 0.5–1 mL of blood. Hemostasis was then achieved. All patients were encouraged to press the auricular needle sticker twice a day for 2–3 minutes. The treatment included a total of three courses (4 weeks = one course).

In Pang et al. [24], the experimental group were treated with ZHU Lian inhibition type 1 acupuncture at the LI4 (Hegu), ST44 (Neiting), GB14 (Yangbai), ST2 (Sibai), CV6 (Qihai), SP10 (Xuehai), and SP9 (Yinlingquan) acupoints and at the site of the acne lesions. The acupuncturists selected 0.25 × 25 mm and 0.25 × 40 mm disposable sterile needles, and inserted the needle perpendicularly and gently to the skin, twisting the needle in counterclockwise rotation, to achieve the de-qi response. The highest points of the acne lesions were located. Then, a total of three acupuncture needles were inserted to a depth of 5–8 mm centripetally in all directions. The treatment was conducted once every other day. The participants underwent two treatment courses (seven times = one treatment course), totaling to 14 times over 4 weeks. The comparison group was treated with Danshentong capsules (1 g, three times per day) and topical application of 0.1% adapalene gel once every night for 4 weeks. The participants were instructed to apply the gel thinly to the affected area after disinfecting with an ethanol- or iodine-impregnated cotton swab, and then, dried with a clean cotton swab.

3) Assessment tools

The Skindex-16 scale, Dermatology Life Quality Index (DLQI), extent of the skin lesions, clinical effectiveness rate (ER), Global Acne Grading System (GAGS), and/or the acne-specific QoL (Acne-QoL) questionnaire, were used for the evaluation of the four studies.

The Skindex-16 scale comprises 16 items, which are divided into the following three aspects: symbols, emotions, and functioning. The Skindex-16 scale score ranges from 0 to 100 points, with lower scores indicating better QoL. In Jiao et al. [21], patients completed the Skindex-16 questionnaire before, during, and after treatment to evaluate the patients’ QoL. Additionally, Jiao et al. [21] used the DLQI to evaluate the skin disease-related QoL, compared the number of acne spots (including non-inflammatory acne) before and after treatment, and evaluated the patient’s experience of itching and pain using the visual analog scale. DLQI [25] is a questionnaire with a score ranging from 0 to 30, with the higher the score, the better the patient’s QoL. DLQI is similar to the Skindex-16 scale.

ER was commonly used in the studies of Zhao [22] and Pang et al. [24]. Moreover, the lesion status before and after treatment was calculated and scored, and the grade was evaluated according to the rate of improvement after treatment. Zhao [22] demonstrated that the ER was higher in the experimental group than in the comparison group (94.29% vs. 77.14%, p < 0.05). Similarly, Pang et al. [24] showed a higher ER in the experimental group than in the control group (95.1% vs. 82.9%, p < 0.05). Although the ER was used for evaluation in both studies, Zhao’s [22] study only selected two evaluation scales that compared the ER and number of spots with skin diseases before and after treatment, resulting in a lack of diversity of data. Contrarily, Pang et al. [24] utilized varied evaluation methods, including GAGS, Acne-QoL, comparisons of the tumor necrosis factor (TNF)-α and interleukin (IL)-6 levels, and ER before and after treatment.

GAGS is a comprehensive acne rating system that evaluates the degree of acne by classifying and scoring the skin lesions by location. In Gao et al.’s [23] study, the effect was evaluated before and after treatment using GAGS. The skin lesions were evaluated according to their locations, which were as follows: back, nose, left cheek, right cheek, lower jaw, and forehead. The GAGS score was calculated by selecting the most serious skin lesion type (acne, papules, pustules, and nodules) in each location (0 point = no skin lesion, with the score increasing by 1 point from acne to papules, pustules, and nodules). The overall classification was 1 to 18 points as mild, up to 30 points as moderate, and over 31 points as severe acne. All three experimental groups showed lower GAGS scores over time, indicating that the condition of the skin lesion improved with each treatment session. Pang et al. [24] also showed a lower GAGS score after the treatment in both the experimental and comparison groups. However, the post-treatment score was significantly lower in the experimental group (12.9 ± 1.7) than in the comparison group (15.9 ± 1.8) (p < 0.05).

The Acne-QoL questionnaire was mutually used in Gao et al. [23] and Pang et al. [24] studies for evaluating the outcomes. Therapeutic efficacy was evaluated according to the change in the scores before and after treatment. The QoL questionnaire is normally used in studies as a measure for evaluating the patient’s QoL. The Acne-QoL is composed of 14 items (self-awareness, social role, emotional role, and acne symptoms) that are specific to acne vulgaris patients. The Acne-QoL score ranges from 1 to 84, with higher Acne-QoL score indicating a better QoL. Gao et al. [23] showed that the Acne-QoL score of all the three experimental groups increased after each treatment session. In summary, all participants demonstrated higher Acne-QoL scores after treatment as compared to that before treatment. Pang et al. [24] also showed higher Acne-QoL scores after the treatment in both the experimental and comparison groups. It is interesting to note that, although the pre-treatment score was higher in the comparison group (33.5 ± 1.7 vs. 34.0 ± 1.6), the Acne-QoL score after treatment was higher in the experimental group (55.6 ± 2.9 vs. 50.3 ± 2.7) (p < 0.05).

4) Side effects and recurrence rate

Jiao et al. [21], Zhao [22], Gao et al. [23] reported on the side effects and recurrence rates of acupuncture treatment for inflammatory acne. None of them reported any serious side effects. In the study by Jiao et al. [21], three participants developed mild hematomas and seven complained of pain, itching, and redness, but no patient developed any serious adverse reactions requiring further actions. Gao et al. [23] reported mild hematoma, which resolved without any special intervention, in three patients. No adverse reactions were reported by in Zhao [22] and Pang et al. [24].

Jiao et al. [21] and Zhao [22] did not report any recurrence. In Gao et al.’s [23] study, the recurrence rates after treatment in experimental groups 1, 2, and 3 were 4.2%, 8.7%, and 14.3%, respectively, showing a non-significant difference (p > 0.05). Furthermore, Pang et al. [24] reported that the recurrence rate of after therapy was lower in the experimental group than in the control group (10.3% vs. 32.4%, p < 0.05).

5) Analysis of studies on externally applied treatments

Given that the literature review of Sung et al. [17] included papers up to May 2018, only a total of three papers on externally applied treatments for acne vulgaris were included in the analysis, including three RCT studies by Yang et al. [26], Jaturapisanukul et al. [27], and Zhang et al. [14]. Table 2 shows a summary of the details of these three studies. Overall, the data of 329 (218 female, 95 male, and 16 patients dropped out) patients from the three studies were analyzed. None of these studies reported any serious side effects.

Table 2 . Study analysis: externally applied treatment for acne vulgaris.

First author (year)	Sample size	Intervention group (A)	Control group (B)	Outcome measurement	Results	Adverse effects
Yang [26] (2021)	(A) n = 30 (B) n = 30	Herbal extract cleanser (mangosteen, Lithospermum officinale, Tribulus terrestris L., Houttuynia cordata Thunb) applied twice a day for 8 weeks	Vehicle cleanser applied twice a day for 8 weeks	1. TLC (IL, NIL) 2. IGA score 3. Satisfaction score 4. Immunohistochemistry staining	1. IL: A > B (p = 0.005)NIL: A > B (p = 0.028) 2. No difference (p = 0.469) 3. No difference 4. A > B: IL-1α, IL-8, keratin 16 reduction	Not severe events
Jaturapisanukul [27] (2021)	n = 49	Water-soluble herbal acne patch applied once a day from 8 pm to 6 am for 11 days	Hydrocolloid acne patch applied once a day from 8 pm to 6 am for 11 days	1. Median time to resolution 2. TLC 3. Mean diameter of IL 4. Erythema score 5. Lightness score 6. Satisfaction scale	1. (A) 4 days(B) 6 days (p < 0.001) 2–4. A < B (p < 0.05) 5. A > B (p < 0.05) 6. A > B	Not severe events
Zhang [14] (2020)	(A) n = 110 (B) n = 110	Modified Qufeng Runmian powder (145 g/bag) applied once daily for 4 weeks	Placebo (145 g/bag) once daily for 4 weeks	1. ASS 2. DLQI 3. VISIA score 4. Skin assessment	1. (A) 83.5%(B) 31.7% (p < 0.01) 2. A < B (p < 0.01) 3. A > B (p < 0.05) 4. A > B (p < 0.01)	Not severe events

TLC, total lesion count; IL, inflammatory lesion; NIL, non-inflammatory lesion; IGA, Investigator’s Global Assessment; ASS, acne severity score; DLQI, Dermatology Life Quality Index; IL-1α, interleukin-1α..

Yang et al. [26] divided 60 acne patients into the experimental and control groups in a 1:1 ratio, with 30 patients in each group. Of the 60 patients, 38 were female and 22 were male, and no remarkable difference was found between the two groups. All patients were instructed to apply herbal extracts or vehicle cleanser on their acne spots twice a day (every morning and evening) for 8 weeks. They were recommended to not use any other treatments during the study period. In the experiment group, the participants were provided a facial cleanser made of mangosteen, Lithospermum officinale, Tribulus terrestris L., and Houttuynia cordata Thunb extracts. In the control group, the participants were given a vehicle cleanser with similar appearance to the cleanser provided for the experimental group.

Jaturapisanukul et al. [27] conducted a split-face study in which the patient’s face was divided in half, with one side set as the experimental side and the other as the control side. Among the 49 patients, 32 were female and 17 were male. All participants received two types of acne patches. In the experimental side, a water-soluble herbal acne patch (WHAP) with three active constituents, including Aloe vera, Calendula officinalis (4.5% w/w), Centella asiatica (4.5% w/w), and Phyllanthus emblica (2.5% w/w) extracts, were applied. The comparison patch used was a hydrocolloid acne patch (HAP) (Nexcare Acne Patch; 3M). Patients were instructed to apply the HAP on one side and the WHAP on the other side once a day from 8 pm to 6 am of the next day. They are allowed to use it on every inflammatory acne lesions on each side of the face for 11 days.

Zhang et al. [14] recruited 220 acne patients who were then equally divided into the treatment and comparison groups, respectively. Of the 220 patients, 6 patients were dropped out, 148 were female, and 56 were male. And there was no remarkable difference between the two groups. The treatment group received MQFRMP (145 g/bag) and 5 mg of MQFRMP was applied once a day for 4 weeks. MQFRMP is a Chinese medicine powder derived from a prescription in Cixi Guangxu Medical Repertoire, which is composed of Bombyx mori Linnaeus, Poria cocos Wolf, Kaempferia galanga L., Curcuma longa L., and Phaseolus radiatus. Patients mixed the powder with 30 mL of warm water (38℃), stirred, applied it on the lesions, and massaged for 30 seconds. After 1 minute, they were washed off. The comparison group got a placebo powder made of maize, purple rice, and tartary buckwheat. The method of applying to the skin was the same as that of the experimental group.

Acne is a constantly recurring inflammatory condition of the hairy sebaceous glands that often begin at puberty and continues to adulthood up to the approximate age of 25 years. Although the etiology of acne vulgaris is unclear, the following have been proposed as contributing factors: 1) increased sebum caused by male hormones; 2) abnormal hyperkeratosis, resulting in pore obstruction of the hair follicles; 3) increased abundance of P. acnes; 4) inflammatory reactions; 5) abnormalities in the skin barrier function; 6) genetics; 7) environmental factors; and 8) stress [28]. P. acnes cause acne vulgaris by producing bacterial metabolites that stimulate the hair follicles to change to pustules or by decomposing triglycerides to form free fatty acids [29].

In Korean medicine, the patient’s condition is treated to address the symptom of acne vulgaris, including ”lowering the body’s heat and detoxifying,” “supplementing the whole body with the moisture,” “strengthening one’s digestive function,” or “improving one’s blood circulation” [30]. The mechanism of pain control in acupuncture treatment is based on the control of the peripheral nervous system, by releasing endogenous opioid-mimicking molecules from the brain and afferent neural pathway of the spinal cord. Contrastingly, the topical analgesic effects may be due to the local release of adenosine caused by microscopic trauma [31]. Additionally, the activation–reduction effects of the pro-nerve growth and pro-inflammatory factors, including TNF-α, interleukins (IL-1β and IL-6), matrix metalloproteinase-9, nitric oxide synthase, and cyclooxygenase, have also been suggested [32]. Huang et al.’s [33] study reported that acupuncture treatment provided excellent effects on 1,068 participants diagnosed with mild-to-severe acne conditions and also suggested that this treatment is appropriate for various types of acne vulgaris and other similar skin lesions.

Currently, the Western medicine treatment for acne vulgaris includes extraction, steroid injection, as well as the administration of topical antimicrobial agents, topical vitamins or benzoyl peroxide agents, and oral antibiotics or hormones (e.g. isotretinoin) [34]. However, the National Institute for Health and Care Excellence’s guidance suggests that antibiotics (both local application and oral) should only be used for a maximum of 6 months, except in particularly exceptional cases [35]. Additionally, with increasing concern for antibiotic resistance, therapeutic alternatives are urgently needed. Considering the data from our four RCT studies, with a high level of evidence, Oriental medicine treatment is effective for acne, and acupuncture treatment should be considered.

The present study conducted a comprehensive search using multiple databases (including CNKI as well as international and domestic databases). Altogether, we found a total of 532 papers, but we excluded 185 papers with duplicates and 337 articles published before 2016 that were not RCT papers, or that used inappropriate treatment methods, leaving 10 studies for further assessment. Finally, four RCT studies were eligible and included for analysis after excluding six papers with no full texts or with only the protocol published. This study analyzed the data of 331 (127 male, 204 female) patients from four RCTs.

The selected acupoints included LI4 (Hegu), ST44 (Neiting), LI11 (Quchi), CV14 (Dazhui), ST36 (Zusanli), BL13 (Feishu), SP10 (Xuehai), GB14 (Yangbai), ST2 (Sibai), CV6 (Qihai), SP9 (Yinlingquan), CO14 (Fei), TF4 (Shenmen), CO18 (Neifenmi), and/or TG2P (Shenshangxian) were used in four RCTs. LI4 (Hegu) and LI11 (Quchi), which were used in two studies or more. The use of these acupoints is consistent with that reported by Cho and Kim [36] who analyzed 17 studies on acupuncture treatment for acne vulgaris.

Zhao [22] utilized vitamin A acid cream in both their experimental and comparison groups, whereas the experimental group received Maehwa acupuncture treatment. The experimental group had higher ER than the comparison group. Maehwa acupuncture is a traditional treatment that involves inserting several needles into the skin. Recently, it has been developed further and used as MTS [37]. The high ER in Zhao’s [22] study may be due to the natural collagen regeneration via the skin’s wound healing mechanism [38].

The Skindex-16 scale, DLQI, assessment of the severity of the skin lesions, clinical ER, GAGS, and/or the Acne-QoL were used for evaluation in the four studies analyzed. ER was used as an evaluation scale in two of the analyzed studies and also in Kim et al.’s [39] study that reviewed 31 papers on fire needle treatment for acne vulgaris. Given that most studies on acupuncture treatment for acne vulgaris use ER in their evaluation, the results of the present analysis may show even greater significance if ER was used in all four studies. The Skindex-16 scale can be used as an overall evaluation scale or for the evaluation of specific aspects, including symptoms, emotions, and functions [40]. Szabó et al. [41] have reported that, although the DLQI and Skindex-16 scale are the most frequently used QoL scales among patients with skin diseases, the Skindex-16 may be more suitable for evaluating the patient’s self-perceived QoL [42]. In the present study, it is believed that not only a simple comparison of the ER, but also evaluating the patients’ overall QoL and the effect felt by the patient using the Skindex-16 scale could have been confirmed in various aspects.

Contrarily, Gao et al. [23] used the Acne-QoL, which consists of four evaluation subscales (self-perception, social, emotions, and symptoms). According to Fehnel et al. [43], disease-specific questionnaires, such as the Acne-QoL, are more relevant and have better consistency, sensitivity, and reliability for measuring disease-specific changes in function, whereas the general QoL questionnaires are preferred for assessing diseases as a whole. In Gao et al.’s [23] study, although only GAGS and Acne-QoL were used in the evaluation, overall evaluation was possible by observing the objective changes in acne symptoms using the GAGS and by assessing the subjective changes in the patients using the Acne-QoL questionnaire.

Among the three papers on externally applied treatments, only Jaturapisanukul et al. [27] utilized both cheeks of the participants as the experimental and comparison sides. Additionally, the treatment effect among the three papers was compared using the most diverse evaluation scale, with the experimental group showing significantly better results in all six evaluation scales. The reliability is increased by the fact that the effectiveness of WHAP was quantitatively and objectively evaluated in terms of recovery time and lesion condition, and at the same time, the qualitative evaluation was not missed with the satisfaction scale. However, it would have been better if the qualitative evaluation had been conducted using a detailed questionnaire, such as the Acne-QoL, and for period a longer than 11 days, rather than simply conducting a satisfaction survey in five stages. Therefore, given that various studies on externally applied treatments for acne have been conducted, it will be meaningful if a systematic review paper that includes more RCTs is published in the future.

The present study has some limitations. First, only four studies were eligible for analysis, which is insufficient to conclude the efficacy of acupuncture treatment in acne vulgaris. Second, due to the use of different evaluation scales, performing comparisons among the studies were not ideal. Third, in Jiao et al.’s [21] study, significant results were expected by using the same acupoints during the treatments in the experimental and control groups (acupuncture vs. sham acupuncture treatment). To minimize blinding errors, an actual penetrating sham acupuncture treatment was performed. Regrettably, the results between the two groups did not vary remarkably. Perhaps, if the control group underwent a non-penetrating type of sham acupuncture treatments, the results would have changed. To increase evidence supporting acupuncture treatment for acne, further large-scale RCT studies need to be conducted in the future.

A total of 4 RCT studies were selected and analyzed according to the research strategy defined in this paper. The results of the analysis are as follows.

1. The findings of this study support the fact that acupuncture is a reliable alternative option for the treatment of inflammatory acne vulgaris.

2. As a result of analyzing the RCT study on the treatment of external applications using herbal medicines for inflammatory acne, all three papers obtained significant results compared to the control group. This also support the fact that external applications using herbal medicines can be another effective treatment option for inflammatory acne vulgaris patients.

3. In order to provide objective evidence for the efficacy of acupuncture for treatment of inflammatory acne vulgaris, a large-scale RCT studies and wider range of case reports will be required. In addition, the use of standard and objective evaluation scale should be included in further studies.

Conceptualization: HJ, YSL. Data curation: HJ. Formal analysis: HJ. Methodology: HJ, YSL, WJ, HK. Project administration: YSL. Supervision: YSL. Visualization: HJ, WJ, GYY, HK. Writing – original draft: HP, SK. Writing – review & editing: HJ, YSL, HP, SK, GYY, HK.

The authors have no conflicts of interest to declare.

None.

This research did not involve any human or animal experiments.