Pediatric Chronic Musculoskeletal Pain: Diagnosis and Management

Chronic musculoskeletal pain (CMP) is defined as pain occurring in the bones, joints, and body tissues for more than 3 months and encompasses amplified musculoskeletal pain syndromes (AMPS), benign limb pain of childhood (eg, growing pains, benign nocturnal limb pain of childhood), benign joint hypermobility syndromes, back pain, skeletal defects, and overuse syndromes.^1,2 After headaches and abdominal pain, CMP is the most frequent type of persistent pain in children and adolescents, with a prevalence of 5% to 8%. The prevalence is known to be higher in older vs younger children and in girls vs boys.¹

CMP affects children’s health-related quality of life and represents a sizable financial burden, estimated at $19.5 billion annually in the United States.¹ Young patients with CMP may have anxiety, depression, low self-esteem, and other comorbidities.¹

When Patients Need Referral to a Rheumatologist

Self-reports and observation may provide adequate assessment of CMP in children ages 3 to 7 years using simple descriptors (eg, a little pain, a medium amount of pain). In children older than 7 years, a numeric pain scale may be used, and in the youngest patients, the Revised FLACC (facial expression, leg movement, activity, cry, and consolability) may help clinicians evaluate pain.¹

Pediatric patients should be able to report the impact that pain has on their daily activities (eg, school, play, sleep, and emotions).¹ Most children and adolescents with CMP need treatment beyond relieving the pain with rest, ice, heat, analgesics, physical therapy, and cognitive behavioral therapy. Some patients exhibiting neurologic or systemic symptoms (eg, fever, fatigue, weight loss), a persistent limp, or worsening focal pain may need to be referred to a rheumatologist.

Amplified Musculoskeletal Pain Syndrome

When pediatric patients with CMP do not show improvement over time and their pain intensity varies — especially when they have hyperalgesia —a diagnosis of AMPS should be considered.¹ The 2 main types of AMPS are localized AMPS or complex regional pain syndrome (CRPS), and diffuse AMPS or juvenile fibromyalgia syndrome (JFMS).

CRPS is a combination of neuropathic pain, inflammation, and peripheral and central nervous system involvement. Genetic factors as well as stressful events may also contribute to the disorder. In children 5 to 15 years old, CRPS has an incidence of 1.2 per 100,000 and is more prevalent in girls. Patients often describe the pain as stabbing, burning, or shooting. In addition to muscle weakness, there may be swelling, hyperhidrosis, and changes in skin color. Criteria from the International Association for the Study of Pain and the Budapest Criteria are commonly used to diagnose this pain syndrome. If the pain persists and is not treated in a timely fashion, contracture could occur.

A more intense version of CMP, diffuse AMPS/JFMS yields higher pain scores, in the moderate to severe range. As a result, patients may experience disrupted sleep and poor school attendance. Although the mechanisms involved in JFMS are not clearly understood, clinicians speculate that, as has been observed in adults with fibromyalgia, children with the syndrome may have abnormal pain processing. The adult fibromyalgia questionnaire from the American College of Rheumatology may be used to diagnose JFMS. The syndrome is more common in adolescent girls, with an overall prevalence of 2% to 6%.

Managing Pediatric Pain

The management of pain and sleeplessness in children and adolescents with CMP can be challenging, as many of the approved pharmacotherapies are used off label. Multimodal management of chronic pain in children and adolescents has proven more effective than sole treatment of physical symptoms.² Physical therapy is necessary to relieve pain and restore movement, however, clinicians are now adopting a biopsychosocial approach to the management of CMP.² When combined with education, psychological, and social therapy, physical therapy may yield outcomes superior to those achieved with physical treatment alone. One study showed that when patients gain an understanding of the mechanisms underlying their pain, they are more adept at coping with the discomfort and limitations.²

Clinicians need to dispel “the belief that pain has a pathological cause, [and that] the severity of pain [is] a reflection of structural/tissue damage,” said John Booth, PhD, senior lecturer of the School of Medical Sciences at the University of New South Wales in Sydney, Australia. “Biomedical treatments which focus on the tissues fail to acknowledge the multifactorial nature of pain as per the International Association for the Study of Pain’s definition of pain, ‘an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage’ and contradict contemporary pain rehabilitation practices.”³

Preventing Pain in Active Patients

One of the most preventable injuries in young athletes is caused by overuse, which can lead to pain in the physis — the site of growth in the long bones of children and adolescents — or growth plate, the weakest part of the bone.⁴ A meta-analysis of 24 studies of physeal injuries indicated that half of the clinicians recommended active rest or light physical activity from 4 weeks to 6 months, depending on the severity of the injury.⁴

“Periods of accelerated growth, chronological age, skeletal maturity, and history of previous injury can predispose young athletes to repetitive stress injuries,” said lead author Amanda Arnold, PT, DPT, OCS, SCS, from the University of South Carolina in Greenville. “Modifiable risk factors such as flexibility, strength, and training volume should be regularly monitored in an effort to limit risk-prone activities and prevent injuries when possible.”⁴

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References

1. Weiss JE, Stinson JN. Pediatric pain syndromes and noninflammatory musculoskeletal pain. Pediatr Clin North Am. 2018;65(4):801-826.

2. Booth J, Moseley GL, Schiltenwolf M, Cashin A, Davies M, Hübscher M. Exercise for chronic musculoskeletal pain: a biopsychosocial approach. Musculoskeletal Care. 2017;15(4):413-421.

3. International Association for the Study of Pain. IASP Terminology. http://www.iasp-pain.org/Education/Content.aspx?ItemNumber=1698. Updated December 14,2017. Accessed August 12, 2018.

4. Arnold A, Thigpen CA, Beattie PF, Kissenberth MJ, Shanley E. Overuse physeal injuries in youth athletes: risk factors, prevention, and treatment strategies. Sports Health. 2017;9(2):139-147.