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With a prevalence as high as 15%, chronic pain is increasingly
being recognized as a common problem in children and adolescents,1 but
one that is still poorly understood. This chapter describes evolving
concepts of several syndromes in which musculoskeletal pain is a
prominent feature. Interestingly, these pain syndromes frequently
have overlapping features. However, most children can be readily
diagnosed by the typical pattern of somatic complaints and the salient
physical findings specific to each syndrome.
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“Growing pains” are the most common cause of
recurrent limb pain in childhood, and references to it have can
be found in the medical literature dating back more than 150 years. Growing
pains occur in children between the ages of 3 and 12, and are characterized
by intermittent nighttime nonarticular aching or pain most commonly
in the legs. Recent prevalence estimates vary from less than 3%2 to
as many as 36.9% in 4 to 6 year olds in Australia.3 An
extension of the syndrome in adolescents and adults may include
restless legs syndrome. In one recent population study, the prevalence of
restless legs syndrome was found to be 1.9% in 8 to 11
year olds and 2% in 12 to 17 year olds; a history of growing
pains and sleep disturbances was more common in the study population.4 Interestingly,
restless legs syndrome also is reported to be common in patients
with fibromyalgia, another pain syndrome which is described later
in this chapter.5The pathogenesis of growing pains
is unknown. Despite the name, it is almost certainly not owing to
growing.6 Perhaps this term is used because the
condition occurs in children (who are always growing), and does
not occur in adulthood (after cessation of growth). Theories have abounded
about the etiology, and have included overuse, anatomic abnormalities,
perfusion problems, and emotional issues, but most have not been
supported by subsequent research.7-10 Recently,
investigators have shown that children with growing pains may have
increased pain sensitivity11 and decreased bone
strength as measured by quantitative ultrasound.12
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Growing pains are typically bilateral, usually occurring in the
evening or at night, and not associated with limping or limited
mobility. There is no history of trauma or infection, and objective
findings are lacking on physical examination. The areas most frequently
involved include the thighs, calves, and, occasionally, the forearms
and trunk. In contrast to patients with juvenile idiopathic arthritis
(JIA), who usually have more pain and stiffness when first arising
in the morning, these children are usually asymptomatic in the morning.
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Parents of children with growing pains report no swelling, color
changes, or warmth of the affected limb. The physical examination
is unrevealing. X-rays and laboratory tests may be necessary to
alleviate parental concern,13 but if the clinical
picture is typical, they are not necessary. In contrast to patients
with juvenile idiopathic arthritis (JIA), who usually have more
pain and stiffness when first arising in the morning, these ...