Video Abstract
Up to one third of children may be diagnosed with growing pains, but considerable uncertainty surrounds how to make this diagnosis. The objective of this study was to detail the definitions of growing pains in the medical literature.
Scoping review with 8 electronic databases and 6 diagnostic classification systems searched from their inception to January 2021. The study selection included peer-reviewed articles or theses referring to “growing pain(s)” or “growth pain(s)” in relation to children or adolescents. Data extraction was performed independently by 2 reviewers.
We included 145 studies and 2 diagnostic systems (ICD-10 and SNOMED). Definition characteristics were grouped into 8 categories: pain location, age of onset, pain pattern, pain trajectory, pain types and risk factors, relationship to activity, severity and functional impact, and physical examination and investigations. There was extremely poor consensus between studies as to the basis for a diagnosis of growing pains. The most consistent component was lower limb pain, which was mentioned in 50% of sources. Pain in the evening or night (48%), episodic or recurrent course (42%), normal physical assessment (35%), and bilateral pain (31%) were the only other components to be mentioned in more than 30% of articles. Notably, more than 80% of studies made no reference to age of onset in their definition, and 93% did not refer to growth. Limitations of this study are that the included studies were not specifically designed to define growing pains.
There is no clarity in the medical research literature regarding what defines growing pain. Clinicians should be wary of relying on the diagnosis to direct treatment decisions.
The synthesis of such heterogeneous data and opinion information published over a span of more than 50 years inevitably failed to achieve a modern concept of the nature and diagnosis of growing pains. Recent research is leading to a better defined syndrome3, which, it is acknowledged, will continue to require further modification, testing and authoritative consensus.
“Growing pains” is an historical term from the nineteenth century, has appeal in the English lexicon, but there is no evidence that it causally relates to growth. No conclusion could be reached about pain category in that ICD-11 classification has been too recent for most included articles. No risk factors were identified. It was stated that “etiology is unknown” despite the citation of genetic evidence (reference 3) and other pre-publication genetic evidence4. Growing pains has had a long association with restless legs syndrome3 (references 23, 25, 28, 89,90) and these conditions are phenotypically very similar. This incompletely resolved association has etiological implications.
The authors, having performed extensive basic research are now in a position to write a narrative or systematic review which could include the following:
• What is the diagnostic category of pain according to ICD-11?5 In the absence of demonstrable pathology, and not meeting criteria for nociceptive or neuropathic pain, the growing pains syndrome is provisionally best defined as a primary pediatric pain syndrome5 with central nociceptive hyperexcitability (Pathirana et al, reference 43), and some nociplastic features, predominantly, but not exclusively, felt in the lower limbs. There is, as yet, no formal pediatric-specific ICD-11 category of chronic primary pain syndrome.
• How is one to make a diagnosis? There has been no authoritative body to determine a consensus about diagnostic criteria. Rather, the currently recommended diagnostic criteria have been serially determined over the years by citation and testing3.
• Given the evidence of genetic influence, is it appropriate now to perform genomic testing, perhaps initially testing for the genes associated with restless legs syndrome?
• Growing pains is confounded by the similar condition painful restless legs syndrome3, and an exclusion clause, urge to move the legs, resulted in a purer phenotype which retained genetic influence. An alternative hypothesis which merits testing is that growing pains is a phenotypic expression of pediatric restless legs syndrome in which younger children experience dominant pain while the urge to move the legs and less pain are more likely to be experienced during later childhood.
References
1. O'Keeffe M, Kamper SJ, Montgomery L, Williams A, Martiniuk A, Lucas B, Dario AB, Rathleff MS, Hestbaek L, Williams CM. Defining Growing Pains: A Scoping Review. Pediatrics. 2022: e2021052578. doi: 10.1542/peds.2021-052578.
2. Munn Z, Pollock D, Khalil H, Alexander L, Mclnerney P, Godfrey CM, Peters M, Tricco AC. What are scoping reviews? Providing a formal definition of scoping reviews as a type of evidence synthesis. JBI Evid Synth. 2022; 20: 950-952. doi: 10.11124/JBIES-21-00483.
3. Champion GD, Bui M, Sarraf S, Donnelly TJ, Bott AN, Goh S, Jaaniste T, Hopper J. Improved definition of growing pains: A common familial primary pain disorder of early childhood. Paediatr Neonatal Pain. 2022; 4: 78-86. doi: 10.1002/pne2.12079.
4. Champion D, Bui M, Bott A, Donnelly T, Goh S, Chapman C, Lemberg D, Jaaniste T, Hopper J. Familial and Genetic Influences on the Common Pediatric Primary Pain Disorders: A Twin Family Study. Children (Basel). 2021; 8: 89. doi: 10.3390/children8020089.
5. Nicholas M, Vlaeyen JWS, Rief W, Barke A, Aziz Q, Benoliel R, Cohen M, Evers S, Giamberardino MA, Goebel A, Korwisi B, Perrot S, Svensson P, Wang SJ, Treede RD; IASP Taskforce for the Classification of Chronic Pain. The IASP classification of chronic pain for ICD-11: chronic primary pain. Pain. 2019 Jan;160(1):28-37. doi: 10.1097/j.pain.0000000000001390. PMID: 30586068.