Growing pains are one of the most common causes of recurrent musculoskeletal pain in children.1
The term first emerged in 1823 in a book called “Maladies de la Croissance” (“Growing Diseases”).2 Reported estimates of the prevalence of growing pains vary from 3.5% to 36.9%. , depending on country, environment and definition.3–7
Although growing pains appear as a popular diagnostic label in children and adolescents, there is uncertainty about what constitutes growing pains.1
Critically, it is unclear whether growing pain is a diagnosis of exclusion for presentations of nonspecific musculoskeletal pain, or whether it is intended as an explanation for a specific musculoskeletal condition or pathology. Many causes have been proposed for growing pains. These include anatomical causes (e.g., hypermobility, genu valgus, low bone mineral density),10 psychological causes (e.g., stress),4,11 vascular causes (e.g., skeletal vascular perfusion),8 and metabolic causes (e.g. , low levels of vitamin D).12
All of these causes are either unsupported by research or supported by inconsistent evidence.9,12–14 This uncertainty means that there is a lack of guidance for clinicians about when the label of growing pains might be appropriate for a patient.
To our knowledge, there is no systematic exploration of how growing pains are defined or diagnosed in the literature. Given the lack of clarity surrounding this popular clinical term, a comprehensive synthesis of how growing pains are currently defined may advance knowledge of this “condition.” The aim of this scoping review was to identify how growing pains are defined in peer-reviewed clinical literature and in diagnostic systems such as the International Classification of Diseases (ICD).
| Methods |
> Data sources
This review was prospectively registered in the International Prospective Register for Systematic Reviews (PROSPERO CRD42019117495) and reported according to the PRISMA extension for scoping (PRISMA-ScR).15 Data were collected from 2 different sources, medical journals and systems. of disease classification.
For studies in medical journals, Medline, Embase, CINAHL, AMED, PEDro, PsycINFO, Scopus and Dissertations and Theses were searched from their inception to January 29, 2021. The search terms “growth* and pain*” were used. in each database. Reference lists were examined and citations of included studies were tracked to identify additional studies.
Two authors independently screened records by titles and abstracts in Covidence. Two authors read the full texts of potentially eligible studies to determine eligibility. Disagreements were resolved through discussion.
For disease classification systems, six databases were evaluated: READ,16 ICD (International Classification of Diseases (ICD)-1017, ICD-11,18 Systematized Nomenclature of Medicine (SNOMED),19 Diagnostic and Statistical Manual of Disorders Mental Disorders (DSM)-520 and International Classification of Primary Care (ICPC)-2.21 Each database was searched with the search terms “growing pain(s)” and “increasing pain(s).
> Selection of studies
All full-length peer-reviewed articles, theses, or dissertations that contained text that referred to the terms growing pain(s) or growing pain(s) in relation to children or adolescents were included.
Conference abstracts, studies with only an abstract available, and studies written in a language other than English where a translation could not be arranged were excluded.
No non-English studies were considered eligible for inclusion. Any medical code referring to growing pain(s) or increasing pain(s) in the 6 disease classification systems was included.
> Data extraction and synthesis
Two authors independently extracted data from studies and disease classification systems. When necessary, study authors were contacted by email to obtain information not reported in the articles.
The following data were extracted from each study: study author, year and country of publication, study design, population and setting description, study objectives, definition and/or diagnostic description for growing pains. The following information was extracted from disease classification systems: name of the database, diagnostic code from the medical record, and definition.
The result was the reported definition of growing pains. Risk of bias (quality) assessment was not considered applicable as this review focused on reporting definitions and diagnostic criteria. 8 components of the definitions were defined and summary statistics of the characteristics within each category were reported.
| Results |
The search identified 2967 unique studies (after removing duplicates). After screening titles and abstracts, 167 studies were retained for full-text evaluation; 145 met the inclusion criteria and were included in the review.
Cross-sectional studies were included (n = 45),9–11,13,22–62 review articles (n = 36),1,8,14,63,94 editorials, comments and perspectives (n = 17),3, 95–110 retrospective observational studies (n = 12),4,111–121 case reports (n = 8),122–129 prospective observational studies (n = 13),7,12,42,130–139 case-control studies (n = 3),140–142 systematic reviews (n = 2),143-144 case series (n = 2),145,146 a thesis,147 a content analysis,148 a randomized trial,149 a reliability and validity study, 30 a before and after study,150 a quasi-experimental study,151 and a qualitative focus group study152 (n = 1 each).
The search for the 6 disease classification systems16–21 recovered 3 diagnostic codes for growing pains; 2 systems (ICD-10 and SNOMED) provided a definition or criterion. Forty-one included studies (28%) did not provide a definition or criteria for growing pain.7,10,25,32,33,49,50,59–61,64,71,72,84,85,88 ,97,98,105,109–113,115,117,119,121–124,126–131,137,139,148,152
The characteristics of the definitions in the other 104 studies (72%) were categorized into 8 components: location of pain, age of onset, pattern of pain, trajectory of pain, type of pain and risk factors, relationship with activity, severity and functional disability, and physical examination and investigations.
| Definitions and diagnostic criteria |
1. Location of pain
Forty-five studies (31%) stated that growing pains are bilateral in nature, and 1 study indicated that growing pains are generally unilateral. The remaining 99 studies (68%) did not specify uni- or bilaterality.
Seventy-two studies (50%) stated that growing pains mainly affect the lower limbs or legs, and of these, 27 studies specifically mentioned the popliteal fossa and 13 the knees and tibia. Other locations mentioned were arms (n = 8), shoulders, back, groin, or ligaments and tendons (all n = 1). Fifty-seven studies (39%) did not mention the location of growing pains.
Forty studies (28%) stated that growing pains were not joint related (i.e. non-joint pain), and 3 stated that they were. There were 102 studies (70%) that did not refer to joint involvement. Thirty-nine studies (27%) stated that growing pains were muscular, while 106 studies (73%) did not refer to muscular involvement.
A diagnostic system specified bilateral symptoms in the lower limbs (SNOMED).
2. Age of onset
Twelve studies (8%) stated that growing pains occur between 3 and 12 years, and most other studies reported a similar range, with only 3 studies expanding the age range to 13, 14, and 15 years, respectively. . One hundred and twenty-two studies (83%) did not refer to age of onset.
3. Pain pattern
Seventy studies (48%) stated that growing pains occur only in the afternoon or evening, and 75 studies (52%) did not mention evening or nighttime pain. Thirty-one studies (21%) stated that growing pains are absent in the morning, while only 1 reported a possible morning presence. There were 113 studies (78%) that made no reference to morning time.
There was a wide variation in the duration of the episodes, ranging from minutes to hours (n = 313,35,136), 30 to 60 minutes (n = 1), 30 minutes to 2 hours (n = 1), less than 72 hours (n = 5), and more than 72 hours (n = 1).
One diagnostic system described growing pain as nocturnal and generally lasting a few minutes (SNOMED).
4. Pain trajectory
Sixty-one studies (42%) stated that growing pains are episodic or recurrent, 21 (14%) stated that they are often persistent in nature, and 16 of these stated that a diagnosis of growing pains can only be made if the child or adolescent has pain for more than 3 months. Seven studies (5%) specifically stated that growing pains are not persistent in nature.
Four studies (3%) stated that growing pains occur daily, while 2 studies (1%) stated that they occur once or twice a week. Individual studies indicated that growing pains occur at least once a month and at least twice in 1 year.
Three studies (2%) mentioned that growing pains resolve with time and maturity. Seventy-one studies (49%) did not address the trajectory of growing pains.
One diagnostic system described growing pains as episodic (SNOMED).
5. Type of pain and risk factors
Nineteen studies (13%) addressed the vague or unknown nature of growing pains.
Seven studies (5%) stated that growing pains are or may be related to growth, 2 studies (1%) stated that they are unlikely to be caused by growth, and 1 study indicated that growing pains occur during a period of decelerated growth. The remaining 135 studies (93%) did not address the relationship between growth and growing pains.
Ninety-six studies (66%) did not address the type of pain or possible causes of growing pains.
One diagnostic system described growing pain as having “other cause” or “unspecified cause” (ICD-10), and 1 as having “no cause” (SNOMED).
6. Relationship with the activity
Fourteen studies (10%) stated that growing pains do not interfere with the ability to engage in physical activity, and 120 studies (83%) did not address the relationship between activity and growing pains.
7. Severity and functional impact
Seventeen studies (12%) stated that pain intensity can vary from mild to severe, and 128 studies (88%) did not address pain intensity.
Twenty-four studies (17%) stated that people with growing pains have no limitations in the ability to walk or exercise, while 4 studies (3%) stated that individuals may experience difficulty walking. There were 117 studies (81%) that did not address functional limitations.
Fifteen studies (10%) mentioned that people with growing pains may have difficulty sleeping or may wake up at night, and 130 studies (90%) did not address sleep.
One diagnostic system described the severity of growing pain as "intense" (SNOMED).
8. Physical examination and investigations
Fifty-one studies (35%) stated that people with growing pains present with a normal physical examination, defined as absence of edema, infection, range of
movement deficits, gait abnormalities, and musculoskeletal disorders, and 93 studies (64%) did not address physical examination findings.
Thirty-one studies (21%) stated that people with growing pains have normal radiography (e.g., radiographic or laboratory findings.
| Discussion |
This scoping review shows that there is no consensus on how to define growing pains and how the diagnosis can be made in clinical practice.
The relevant literature is characterized by contradictions, for example, specifically in the localization in arms vs. lower limbs and in the absence of references to specific defining characteristics such as location, age of onset, or relationship with the activity.
Lower extremity pain (50% of studies), evening or nighttime pain (48%), episodic or recurrent pattern (42%), normal physical examination (35%), and bilateral pain (31%) were the only specific indicators mentioned in at least 30% of the references.
It is particularly noteworthy that more than 80% of the studies did not refer to age of onset in their definitions, and 93% did not refer to growth at all in their definition of growing pains.
The strength of this review is that all study designs were included and that a sensitive search was performed in a number of databases and disease classification systems. Two independent reviewers extracted data.
The review was conducted in line with current recommendations for scoping reviews. A limitation of the review is that the included studies were not specifically designed to define growing pains so some articles may not have explicitly reported definitions or criteria used by researchers in a particular study.
There are sixteen different study designs in this review. The specific objectives of these studies varied, and this may explain some of the variabilities in definitions. Instead, it could be considered a strength that this study captures how diagnosis is reported in research and as such describes what is available to consumers of research evidence in the field.153-155
Although it is the most comprehensive summary of how growing pains are defined and used in research, this is not the first study to point out some major problems with the concept. Several authors have pointed out that growing pains are used as a diagnosis of exclusion,1,156 and furthermore, that the etiology is unknown.87,144
Perhaps the most surprising finding of this review is the disturbing inconsistency in definitions, a result that reinforces calls by Walters et al.90 for standardized diagnostic criteria.
Interestingly, very few studies address the relationship between growth and growing pains , reflecting uncertainty regarding the role of growth as a contributing factor. Furthermore, no conclusion can be drawn from this scoping review about the involvement of growing pain, whether the origin is in the joints or muscles. This is because although 40 of the included studies (28%) stated that growing pains were not joint related, 102 studies (70%) did not address joint involvement.
A similar picture is seen for muscle involvement; 39 studies (27%) stated that the growing pains were muscular, but 106 studies (73%) did not refer to muscle involvement. This lack of clarity along with the generally accepted view that the pathophysiology is unknown increases the possibility that growing pains are a misnomer.
Several of the included studies expressed this issue.14,26,78,81,103 These studies proposed a series of alternative terms: “recurrent pain in the extremities in childhood”, “benign nocturnal extremity pain in childhood”, “pain benign leg pain in children” and “idiopathic extremity pain”.
From a clinical perspective, it may be valuable to better understand the decision-making process around the labels that clinicians use in children and adolescents with musculoskeletal pain. No qualitative study was located on this topic. A survey study showed that physicians feel it is important to order investigations to exclude other pathologies before assigning a diagnosis of growing pains.41
Literature from other areas of health (for example, low back pain, cancer, conjunctivitis, polycystic ovary syndrome, or gastroesophageal symptoms) shows that labels provided to patients to explain health conditions or symptoms can influence beliefs and preferences of treatment.157-161 The relative benefits and harms of providing a diagnosis of growing pains are currently unknown.
Given that prevalence can be as high as 37%, the fact that the pathophysiology is unknown, and the compelling evidence of substantial variation in label application, point to a clear need for a better understanding of pain in children. This echoes previous calls for research to provide clearer guidance for clinical practice.
Specifically, researchers should not use the term growing pains diagnosis itself to categorize study participants or as an explanatory variable.
The term is used so heterogeneously that it will make the study difficult to interpret. If diagnosis is to be used, a clear description of the clinical features used to define growing pains in that particular study is recommended.
The absence of a clear definition of growing pains may lead to misclassification of patients and result in the omission of specific causes of musculoskeletal pain in children or adolescents.
Interestingly, Peterson’s criteria do not refer to growth as a feature of growing pains. The Peterson criteria mention that growing pains generally occur once or twice a week. Most of the studies included in this review did not document this.
The Peterson criteria mention that growing pains are not related to activity or affect activity. Most of the studies included in this review make no mention of activity. So the question remains why the word “growth” is used in the first place.
| Conclusions |
There is great variability and lack of clarity in how growing pains are defined in the literature.
Doctors and researchers who use the term should clearly describe the clinical criteria they use to define growing pains, because the diagnosis itself means different things in different people.
| Comment |
Growing pains are one of the most common causes of recurrent musculoskeletal pain in children. Critically, it is unclear whether this is a diagnosis of exclusion, or whether it may be the explanation for a specific musculoskeletal condition or pathology.
The great variability and lack of clarity in its definition may make it difficult to make a medical decision to classify nonspecific musculoskeletal pain as growing pains in otherwise healthy children. New research is needed to advance knowledge and definition of this highly variable condition.
