Dataset Information

Improved definition of growing pains: A common familial primary pain disorder of early childhood

ABSTRACT: Abstract

Background

Commonly applied diagnostic criteria for growing pains (GP) have evolved without determination by an authoritative representative body. GP and restless legs syndrome (RLS) share anatomical, distributional, temporal, and other clinical features and are associated in individuals over time, in families, and in population samples. In this study, we tested the hypothesis that GP, diagnosed by widely used criteria, is confounded by cases of painful restless legs syndrome (RLS‐Painful).

Methods

A twin family study of genetic influence and associations of GP using questionnaires was administered by Twins Research Australia. Twins (3–18 years; monozygous 503, dizygous 513), their oldest siblings, mothers, and fathers were randomly selected from the twin registry. Family members completed the questionnaires assessing lifetime prevalence of GP by commonly applied criteria and covariates including the history of iron deficiency and pediatric pain disorders. A GP‐Specific phenotype was defined as GP without urge to move the legs. We determined similarities in twin pairs for the GP and GP‐Specific phenotypes, family associations, and estimated familial and individual‐specific associations for each phenotype.

Results

Lifetime prevalence was one‐third lower for GP‐Specific than for GP among the twin and family members. Monozygous twin pairs were more similar than dizygous twin pairs for GP and for the derived GP‐Specific phenotype by three methods, consistent with genetic influence. There were familial associations, but the essential evidence for genetic influence was the twin‐cotwin data. GP was associated, in multivariable analyses, with migraine, headaches, recurrent abdominal pain, and iron deficiency, while GP‐Specific associations were limited to migraine and headaches.

Conclusions

GP is hybrid, one‐third of cases having symptoms and associations of RLS, necessarily RLS‐Painful. GP‐Specific (without symptoms and associations of RLS) could have a genetic etiology. We propose new criteria to facilitate etiological and therapeutic research. Growing pains, a highly prevalent primary pain disorder of childhood, has been associated with restless legs syndrome in individuals over time, in families and in population samples. This conundrum has been clarified by the evidence in this twin family study that growing pains, as previously defined, has been confounded by symptoms of restless legs syndrome. An exclusion clause of urge to move the legs has resulted in criteria for a purer phenotype which retains evidence of heritability.

SUBMITTER: Champion G

PROVIDER: S-EPMC9189907 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Objective This paper reviews ocular pain with the main focus on ocular surface discomfort and dry eye pain. Anatomy, physiology, epidemiology, assessment, and treatment are discussed in this paper. Methods A PubMed search was conducted for studies published from 2000 to 2019 on the anatomy, pathophysiology, epidemiology, assessment, and treatment of ocular pain. Reviews, meta-analyses, and randomized clinical trials were included. Inclusion criteria focused on ocular surface discomfort, dry eye pain and neuropathic pain. Results A total of 112 articles were found through searches, 45 of which were selected and studied in this review. Discussion Pain in general can be acute or chronic. Acute pain is usually a physiologic response to a serious damage to the tissues and alleviates with pain relief treatments. Chronic pain is defined as the persistence of pain for more than three months. From another point of view, pain has been classified into either nociceptive or neuropathic. Nociceptive pain is a physiologic response to a noxious stimulus. Both central and peripheral nervous systems can be involved in the development of a neuropathic pain, which is characterized by positive or negative sensory signs, a pain perceived disproportionate to a noxious stimulus, and/or not responsive to analgesics. Chronic pain usually has a neuropathic component. Ocular surface pain is a well-known complaint after any corneal surgery. This is mainly due to abnormal regeneration of damaged corneal nerve endings and abnormal connections with adjacent nerve endings which produce spontaneous activity. Tear hyperosmolarity and the resultant ocular surface inflammation can also trigger voluntary activity of corneal nerve endings. Referral pain to the first and second division of the trigeminal nerve has been reported. Interference with vision and even sleep, which is out of proportion to the examination are among patients’ complaints. All of these elements proposed the new concept of ocular neuropathic pain syndrome. The first step in conventional evaluation of ocular discomfort is search for tear insufficiency. Pathologies of lid and blinking as well as conjunctival irregularities should be addressed. Anti-inflammatory agents and, in resistant cases, systemic neuromodulators are shown to be helpful. Education on behavioral changes and reassurance are essential steps. Considering the neuropathic origin for the ocular pain, treatment modalities used for such pain in other parts of the body can be considered for this syndrome.