Chronic pain, characterized as pain stemming from various causes that lasts or recurs for more than three months,1 is a health condition that significantly diminishes quality of life. Its classifications include primary chronic pain, pain related to cancer, neuropathic pain, trauma-related pain (including postoperative pain), orofacial pain, secondary abdominal pain, and headaches.1 Children and teenagers often experience specific challenges such as hindrances in academic progress and interpersonal relationships. Furthermore, there are notable economic repercussions and impacts on family dynamics.2,3

Despite the high prevalence of chronic pain, more than 30 % of pediatric cases,3 there is a lack of conclusive studies on the proper management of this condition. The existing ones point to the difficulty of clinical management, due to the multiple functioning areas affected by the desease.4–6 Current evidence suggests that the best approach is an interdisciplinary one, led by specialized teams, composed of physicians, physiotherapists, psychologists, and other professionals. This integrated work promotes changes in different aspects of the patients' lives. Therefore, it modulates the mechanisms of perpetuation and amplification of pain, not just its causal factors.4

These physiological mechanisms involved in the modulation of chronic pain are not yet well established, however, studies point out that the maintenance of symptoms beyond their initial stimulus is related to the reduction of the hypothalamic-pituitary-adrenal axis or to the increase in the sympathetic response to stress.7 These changes result in sensitization of the pain transmission and interpretation pathways, allowing for the chronicization of the pain. In addition, many chronic pain conditions do not present measurable tissue damage, which strengthens the hypothesis that there are mechanisms of interaction between neurotransmitters and mediators that are not yet understood.7

When addressing pain in pediatric patients, it's essential to tailor assessment and management strategies based on age and cognitive development to ensure optimal care8. Utilizing appropriate tools for gauging pain intensity is crucial, as it informs treatment decisions. Additionally, pediatric pain often coincides with anxiety and distress, underscoring the importance of a comprehensive approach that incorporates both pharmacological and non-pharmacological therapies.8

The management of chronically ill children is also made difficult by their frequent use of complementary health practices, reaching up to 50 % of this population,9 even though the level of scientific evidence supporting this use is incipient and controversial. In this sense, Integrative Medicine addresses this problem and seeks to offer an evidence-based practice that meets the patients' demand for more dynamic and comprehensive care.9

Acupuncture is a major exponent of this modality and is being studied for the treatment of various health conditions,10 in addition to the fact that many physiological mechanisms involved in its therapeutic action are already known.11,12 This allows professionals to practice it based on scientific evidence, acting safely and effectively in the clinical management of their patients.

Pain is the largest area of research of acupuncture, with well-designed studies on the neural mechanisms involved and its clinical efficacy, the most relevant being the release of endogenous opioids at the spinal cord.11 In the adult population, acupuncture is already well established as a technique for controlling chronic pain,13 for example, headache, pelvic pain, fibromyalgia, and postoperative pain.10 However, in the field of pediatrics, the number of works is still reduced, and the scientific evidence is not well established,9 which may justify the scarce inclusion of this technique in pediatric pain centers.

One of the difficulties in building scientific evidence on acupuncture has its roots in its history, as there are many techniques and schools of thought, and this lack of standardization becomes a barrier to the consolidation of systematic studies. For example, there are studies that use Chinese systemic acupuncture, Chinese and Japanese scalp acupuncture, and Japanese systemic acupuncture, among other variations.

Moreover, within Chinese Medicine there are other techniques that are commonly used as complements of acupuncture treatments, such as 1. acupressure and moxibustion (other forms of stimulating the acupoints, the first being manual pressure, and the latter being heat stimuli); 2. cupping, which consists in producing a vacuum that stretches the skin and fascia; 3. auricular therapy, a form of stimulating specific points in the ear that produces systemic effects.

Therefore, it is essential to explain the technique and the rationality used when conducting scientific work on acupuncture14. Moxibustion, acupressure, and auricular therapy are of special interest in the field of pediatrics, as they are non-invasive techniques and therefore better accepted by families.

The protocol for this study was registered with the PROSPERO (International Prospective Register of Systematic Reviews) network of systematic reviews, under the number CRD42022303021 and followed the PRISMA statement (Preferred Reporting Items for Systematic Reviews and Meta-Analyses).21

The search was conducted in the MEDLINE, Scopus and Scielo databases. The first survey in these databases took place in September 2022 and was updated in April 2023. The search logic procedure (Table 1) was carried out in stages so that it could include articles that use diverse lexical choices, as well as allow the emergence of those that used other acupuncture techniques.

The preferred study design for inclusion was randomized controlled trials, but prospective studies such as single-arm and case series were also accepted. Review articles, cross-sectional studies, letters, book chapters, and editorials were excluded. There was no restriction on publication date or language.

After reading the abstracts, those articles that analyzed acupuncture (considered as the insertion of an acupuncture needle in any part of the body) or related techniques (such as moxibustion, acupressure, cupping, and auricular therapy) as an intervention for the management of chronic pain, of any origin, and that included participants under 18 years of age or did not report the age of the sample in their abstracts, were selected for full reading. This selection was performed by three researchers independently and the disagreements were resolved collectively.

Articles that analyzed separately or exclusively the pediatric population, which was considered up to 22 years old, following the 2017 guidelines of the American Academy of Pediatrics,22 and that met the criteria described above, were included in the review. The preferred and mandatory outcomes of the search were those of pain intensity and frequency, but others were also analyzed, such as the impact on quality of life.

The included articles were analyzed for quality using the MMAT - Mixed Methods Appraisal Tool,23 in view of the variety of proposed designs. The clinical trial that was selected was confronted with STRICTA - Standards for Reporting Interventions in Clinical Trials of Acupuncture,14 as a complementary study quality analysis.

In total, the searches returned 2369 results (408 in MEDLINE; 1911 in Scopus; 50 in Scielo). After the exclusion of duplicates, 1335 articles remained. These articles were then screened by three researchers (JRB, JURSJ, GPA), who reached a consensus on any disagreements. Applying the selection criteria for study design, target population, and evaluated technique, 16 articles were chosen for full-text reading. Of these, 11 were excluded from the analysis for the reasons explained below, and 5 were included in this review, as shown in the flowchart (Figure 1).

Figure 1.

Flowchart (PRISMA).

(0.24MB).

The reasons for the exclusion of the 11 articles that were read in full include:

• i.

  Three articles did not include children under 18 years of age in the study.

• ii.

  Four articles did not provide pain intensity and frequency data separating pediatrics and other age bands in the analysis; authors were contacted to obtain the necessary information, but there was no response.

• iii.

  Three articles did not quantify the improvement, limiting themselves to saying that there was a report of improvement by the patients or family members.

• iv.

  One article did not evaluate the response to pain.

The five articles included in this review have different designs (Table 2), consequently, the quality analysis was performed by MMAT.23 The articles were of good quality, except for the lack of description of the randomization procedure in the Randomized Controlled Trial (D).

Under the prism of STRICTA,14 article (D) fully met the criteria for the preparation and description of a clinical trial of acupuncture, which demonstrates the care in the development of the protocol and its execution. The points that were not reported in the article in question were presented in a separate article, cited in the text, which discusses in more detail the protocol executed.

Due to the methodological differences and design of the included studies, it was not possible to perform a synthetic analysis of the data or to produce a meta-analysis. Thus, this review is based on an individual and descriptive analysis of the studies in conjunction with a comparative discussion between them, as well as the base literature of the proposed theme.

The present findings reinforce the perception of a small number of clinical studies that evaluate the effect of acupuncture in the management of chronic pain in the pediatric population.

The articles analyzed showed positive results in terms of immediate clinical response, including improvements in quality of life, school participation and social interaction. These are significant impacts for patients who suffer from chronic pain. However, the maintenance of these effects over the long term was not observed in the follow-up of the clinical trial.

The two case series articles (B and C) bring an interesting perspective from a qualitative standpoint. Both describe improvement in school attendance, participation in social and sporting events, and giving patients back the characteristics of childhood that they were losing. They thus demonstrate the individual clinical relevance of acupuncture and the impact that this treatment has on the patients. Further studies should focus on the use of social-educational outcome measures.

The single-arm articles (A and E) showed a larger number of participants and achieved statistical significance of the differences pre- and post-treatment, providing evidence for the clinical use of this technique in cases of pediatric chronic pain. As a strength, these studies included various diagnoses, which are more in line with the IASP recommendations and suggest a broad action of acupuncture on pain mechanisms. However, a major bias present in study A is the concomitant use of hypnosis during acupuncture sessions, as it prevents the separation of the effects of each of the techniques.

The only randomized controlled trial included (D) was placebo-controlled. Surprisingly, effect size indicated a “very significant” effect in pain reduction, but it disappeared at the eight-week follow-up, suggesting that treatment benefit was not persistent. A limitation of this study is its small sample, with the authors stating that the initial calculation was 42 participants, not being able to reach half that value. In addition, the study assesses only chronic pelvic pain due to endometriosis, which cannot be generalized to other forms of chronic pain.

How to conduct a control intervention is an important discussion in current acupuncture research. There are many ways to produce sham-acupuncture, such as needle outside acupoints, minimal insertion of the needle, and non-insertion of needle.32 But, as physiological studies advance, invasive sham-acupuncture show some clinical effects. Therefore, the current evidence suggests that non-invasive needling is the best control for acupuncture but is not well established that is in fact a true placebo.32

This study (D) also performs the dosage of inflammatory mediators in the blood of the participants, finding no statistical difference in the samples. Other studies reached similar conclusions evaluating dysmenorrhea,33 which suggests that the analgesic effects of acupuncture in these cases do not occur through anti-inflammatory pathways.

Despite integrative health practices being widely used in children and teenagers,9,34 clinical studies investigating their efficacy in the management of chronic pain in this population are still preliminary.

Given the importance of chronic pain in pediatrics, both for its prevalence and for the impact it has on patients and families,2,3 this systematic review clearly points to the scarce number of scientific intervention studies, in addition to the variety of methodologies and techniques used. It supports the need for further investigation of the topic.35,36

For example, in study (A), 94 % of the invited patients agreed to participate in the study and 90 % of the participants completed the sessions. In study (D), 77.8 % of the participants completed the 16 sessions. In article (E), only 56.4 % completed the proposed treatment, but the reasons for abandonment did not include non-acceptance or adverse effects, only the difficulty of locomotion and conflict with school and work. This suggests that acupuncture is well tolerated by children and adolescents, which is in line with other articles found in the literature36–38 and can be part of multi-professional protocols for the management of chronic pain in the pediatric population.

In addition, there were no serious adverse events reported in the studies included. Only article (D) reports cases of mild events such as pain at the puncture site, bruises, lightheadedness, and dizziness after the sessions, all of which were transient and without major complications. Knowing that these studies demonstrated care in their execution, with trained and experienced professionals, the practice of acupuncture seems to be safe, strengthening what has already been pointed out in the literature.39,40

In general, the studies included in this systematic review attest to the potential of acupuncture in the symptomatic management of patients with chronic pain, whose effects were not restricted to reducing pain intensity and frequency, but also in the impact of pain on daily activities, such as attending school, and on quality of life. This finding adds evidence that acupuncture seems to be a promising and safe method and the possibility of its inclusion in pediatric pain teams deserves more attention.

However, the scientific strength of this data is still incipient. Given the biases and limitations of these articles, such as the small sample size, the lack of controls, the variety of techniques used, and the lack of follow-up. Even so, it presents a therapeutic possibility, since article (A) showed that 45 % of the participants reported at least 50 % improvement in pain and study (D), which has the best design and adequate methodology as assessed by the tools used, showed a "very significant" magnitude of effect in pain management in a 4-week analysis.

Despite the positive response observed in the studies, the only study with follow-up did not find statistical significance in the follow-up from 8 weeks, which suggests that acupuncture may have a short-lasting effect on chronic pain in pediatrics. Article (C), in its two cases, resulted in cumulative and long-term improvement, as its follow-up lasted for almost a year. This divergence may be due to the methodological differences between the studies, including the proposed treatment, since (D) uses Japanese acupuncture and (C) Chinese acupuncture. In any case, this study aims to investigate the effect of acupuncture methods on pediatrics pain management rather than to directly compare types of acupuncture methods.

This lack of standard in studies involving acupuncture is a present difficulty that has already been discussed in previous articles,36 which originates in its long history and practice by various peoples. So, it is necessary to carry out better studies, with larger samples and control groups, to determine the indications of each technique, and its limitations and increase the certainty of the positive clinical findings.

A limitation of research, including reviews, carried out in the West is the difficulty of access and use of Chinese biomedical databases. This has been discussed in more recent articles, including topics that go beyond Traditional Chinese Medicine, but the authors observed a limitation in access and low frequency of use of these databases.41 Possibly the inclusion of these databases would bring different results in this research, such as more clinical trials and bigger samples, knowing the size of the Chinese population and the prevalence of acupuncture usage in this country. But its execution was not possible.

Another issue that needs to be pointed out is the choice of the term chronic pain. A general term (chronic pain) was adopted to search broadly for various diagnoses, following the current recommendations. However, this choice may have impacted the search, as some articles may use specific terms in their descriptions such as dysmenorrhea, headache and fibromyalgia and may not have appeared in the surveys. At the same time, it would not be feasible to search for all types of chronic pain individually and, given the lack of studies, this broader strategy was chosen.

The studies provided weak scientific evidence to justify the use of acupuncture in children and adolescents with chronic pain, from an interdisciplinary perspective. Although the included studies are favorable to the usage of acupuncture, there are many limitations in their execution.

For example, the main one being the variability of techniques involved in the treatments, such as the concomitant use of hypnosis in acupuncture sessions and other Chinese Medicine techniques, without standardization of therapeutic conduct. Another major limitation is the lack of control groups, which considerably decreases the strength of the results obtained. Only one of the studies performed a group comparison.

In general, there is scant and weak scientific evidence to support the systematic use of acupuncture in the management of chronic pain in pediatrics. However, it seems to be a promising adjuvant therapy, with good clinical impact and no significant adverse effects. However, due to the limited number of articles available and the heterogeneity in their designs and therapeutic proposals, it is not possible to conclude definitively about the clinical relevance of these findings. More studies, especially controlled clinical trials, are needed to validate this hypothesis.