eMedicine Specialties > Pediatrics: General Medicine > Rheumatology

Fibromyalgia

Author: Angelo P Giardino, MD, PhD, Clinical Associate Professor, Department of Pediatrics, Baylor College of Medicine; Medical Director, Texas Children's Health Plan, Inc
Coauthor(s): Eileen R Giardino, PhD, RN, MSN, FNP-BC, ANP-BC, Associate Professor of Nursing, Department of Acute and Continuing Care, University of Texas Health Sciences Center Houston School of Nursing; Gregory F Keenan, MD, Director of Medical Affairs, Department of Immunology, Centocor, Inc
Contributor Information and Disclosures

Updated: Dec 10, 2008

Introduction

Background

Juvenile primary fibromyalgia syndrome (JPFS) is a musculoskeletal pain syndrome characterized by multiple discrete tender points (TPs), fatigue, and sleep disturbance in the child and adolescent. JPFS can be chronic in nature and can require a multidisciplinary approach to the ongoing treatment of the disorder. The pain experienced is modulated by factors such as activity, anxiety, stress, and weather changes. Diagnosis is made on the basis of the presence or absence of specific criteria that have been found to be consistent with those who experience JPFS. The chronic nature of fibromyalgia in the pediatric population suggests consequences on psychosocial development and implications of a more difficult transition from childhood to adulthood.¹   

The core feature of fibromyalgia is widespread musculoskeletal pain, with multiple TPs and other associated features such as fatigue, joint stiffness, skin tenderness, postexertional pain, and sleep disturbance. Other associated features may include irritable bowel symptoms, poor memory, tension headaches, dizziness, fluid retention, paraesthesias, restless legs, bruising, and Raynaud phenomenon. The chronic musculoskeletal pain affects quality of life, whereas fatigability influences motor response and ability to complete activities of daily living in an expedient time frame.^1,2

Adult fibromyalgia syndrome (FMS) diagnosis is based on history, physical examination, and laboratory study findings and exclusion of other causes of findings. The 1990 American College of Rheumatology (ACR) diagnostic criteria for fibromyalgia syndrome include diffuse pain and 11 or more of the 18 identified TPs. The goal of treatment is to control the symptoms using multiple therapies that include medication, physical therapy, exercise, support groups, and psychologic therapy.

The ACR defined 2 major diagnostic criteria for classifying fibromyalgia syndrome in adults. The first is a history of widespread pain for at least 3 months that involves both sides of the body above and below the waist. Specific areas include the cervical skeleton (eg, spine, anterior chest), the shoulders or buttocks (considered for each involved side), and the lower back (considered below the waist). The second criterion requires pain on 11 of 18 defined TPs when digitally palpated with approximately 4 kg per unit area of force. For a positive result, the patient must indicate that palpation is painful (see Physical).

In 1985, Yunus and Masi first compared JPFS with fibromyalgia syndrome in adults.³ The 1990 criteria for adult fibromyalgia syndrome were found to be less sensitive to the events that occur in childhood fibromyalgia syndrome. Yunus and Masi proposed fibromyalgia syndrome criteria that are slightly different for children and adolescents. Their criteria take into consideration a more variable presentation, along with a dependence on adult input to make the diagnosis. JPFS criteria include the presence of 2 major criteria and some minor diagnostic symptomatology.

The diagnostic criteria for JPFS are based on the Yunus and Masi guidelines.³ The ACR criteria for adults has not been validated in children. The Yunus and Masi criteria are as follows:

• Three or more months of widespread musculoskeletal pain
• Five or more well defined tender point sites
• The absence of underlying medical condition causes for the symptoms
• Routine laboratory test results in normal range
• Presence of 3 of the following 10 minor criteria (also referred to as associated symptoms) as stated below:
  • Chronic anxiety or tension
  • Fatigue
  • Poor sleep
  • Chronic headaches
  • Irritable bowel syndrome
  • Subjective soft tissue swelling
  • Numbness
  • Pain modulation by physical activities
  • Pain modulation by weather conditions
  • Pain modulation by anxiety or stress

Although children and adults with fibromyalgia syndrome experience similar symptoms, children seem to have more sleep disturbances. Children experience pain in fewer body areas (3 in children versus 5 in adults) and have fewer TPs areas than adults (5 out of 11 TP areas in children versus 11 out of 18 in adults). The adult criteria were developed by the ACR. Other associated symptoms include headaches, soft tissue swelling, tension, stress, and chronic anxiety. Children have less lower back pain, hand pain, and paraspinal TPs; however, children experience ankle pain and increased pain associated with overactivity.

Pathophysiology

Fibromyalgia syndrome is a physiologic entity rather than a psychiatric disorder. Yunus (2008) suggests a classification of disorders called central sensitivity syndromes (CSSs) that result from changes in the CNS.⁴ Neurochemical pathology of the CNS (spinal cord and brain) causes areas of the body to become sensitized, such that pain is experienced from even mild touch or pressure. The underlying concept of the CSSs is that the 13 disorders have some similar clinical features and a common pathophysiological component of central sensitization (CS). See Causes. Yunus (2008) disputes the idea that the pain that people with CSSs experience is merely psychiatric, psychosocial, or psychological in nature. Although depression and stress may contribute to the symptoms of CSS, they are still based on objective changes in the CNS.⁴
 
The physiology of CS involves a process in which inflammation that may be caused by a minor trauma sets off an involved CNS response that results in pain and distress. The response pathway starts with the initial input that causes the release of bradykinin, prostaglandins, serotonin, and substance P to then activate A-delta and C-fiber nociceptors at peripheral tissues.⁴ Nociceptive impulses travel through fibers to wide dynamic range neurons in the spinal cord. At nerve terminals, activated C-fibers convey neurotransmitters or neuromodulators that barrage impulses at the synapse and hyperexcite postsynaptic receptors. The changes cause hyperexcitability escalation of other neurons, giving rise to hypersensitivity to peripheral stimuli.⁴
 
The enhanced nociceptive (spinal) flexion reflex (NFR) is a consistent objective test for CS obtained by electrically stimulating the sural nerve and then measuring the electromyelographic (EMG) response of the biceps femoris. People with fibromyalgia or other CSSs, have demonstrated an accentuated NFR (or decreased stimulus threshold) which is indicative of CS.⁴
 
Along with the CS response, other physiologic aspects of CSSs include sympathetic overactivity, genetic factors, neuroendocrine dysfunctions, peripheral nociception generators (eg arthritis), environmental stimuli, poor sleep, viral or local infections (may trigger inflammatory mediators that activate nociceptive fibers), nonrestorative sleep, and psychosocial distress.^4,5

Frequency

United States

Estimates of the prevalence of JPFS using the diagnostic criteria guidelines of the ACR are as high as 6%.¹ Most children diagnosed with JPFS are prepubertal or adolescent girls aged 13-15 years.^3,6  In pediatric JPFS, the mean age of onset is 12 years. JPFS appears to be more common in white, adolescent girls, although boys of the same age or younger have also been diagnosed; reported figures indicate as many as 35% of all children diagnosed with the syndrome are boys. JPFS accounts for 7.7% of new diagnoses made among children and adolescents by pediatric rheumatologists. Musculoskeletal pain syndromes, which include JPFS, account for approximately 25% of new referrals to pediatric rheumatologists. JPFS is the diagnosis in 25-40% of children with musculoskeletal pain syndromes.¹

In the United States, fibromyalgia syndrome affects approximately 2% of the population.⁴ Earlier data for the adult population indicated that 0.5% of men and about 3.4% of women are diagnosed with fibromyalgia syndrome.⁷   

Romano (1991) studied 15 children (10 females, 5 males) aged 16 years and younger (mean age, 13 y) in a rheumatology clinic and found that many cases of JFMS go undiagnosed and are confused with other diagnoses.⁸ He reported that 67% visited 3 or more doctors before evaluation by a rheumatologist; 60% were diagnosed with juvenile chronic arthritis, and other misdiagnoses included psychological problems, hysteria, and growing pains.⁸

International

Fibromyalgia syndrome occurs in 6.2% of Israeli school children⁹ and 1.3% of Mexican school children.¹⁰

Mortality/Morbidity

• In a 2000 review of 59 children with pediatric fibromyalgia syndrome, Gedalia and colleagues found the following symptoms:¹¹
  • Generalized aches (97%)
  • Headaches (76%)
  • Sleep disturbances (70%)
  • Stiffness (30%)
  • Subjective joint swelling (24%)
  • Fatigue (20%)
  • Abdominal pain (17%)
  • Joint hypermobility(14%)
  • Depression (7%)
• In 1998, Siegel and colleagues found the following symptoms at the initial presentation of 45 children with fibromyalgia syndrome:⁶
  • Sleep disturbance (96%)
  • Diffuse pain (93%)
  • Headaches (71%)
  • General fatigue (62%)
  • Morning stiffness (53%)
  • Morning fatigue (49%)
  • Depression (43%)
  • Feeling worse with exercise (42%)
  • Subjective swelling (40%)
  • Irritable bowel (38%)
  • Dysmenorrhea (36%)
  • Illness changes with weather (36%)
  • Paresthesias (24%)
  • Global anxiety (22%)
  • Lack of energy (18%)
  • Raynaud phenomenon (13%)
• Studies of children with fibromyalgia syndrome have documented a high association of sleep disturbances. Tayag-Kier et al reported that children with fibromyalgia syndrome presented with long sleep latency, shortened total sleep time, decreased sleep efficiency, and increased wakefulness during sleep.¹² Additionally, Tayag-Kier et al found that a subset of children with fibromyalgia syndrome exhibited periodic limb movement in sleep (PLMS) in which patients experienced significantly higher wakefulness after sleep onset.
• A study of 16 children with JPFS, 16 with arthritis and 16 healthy controls found that children with fibromyalgia demonstrated increased levels of anxiety and depression, more temperamental instability, less family cohesion, and higher pain sensitivity than the other 2 groups. They concluded that the interaction of the associated risk factors of JPFS may explain the severity and breadth of the symptoms of this syndrome.¹³
• In addition, other associated symptoms of fibromyalgia syndrome in children include irritable bowel syndrome, migraines, premenstrual syndrome, Raynaud phenomenon, female urethral syndrome, and restless leg syndrome.

Race

In the United States, fibromyalgia syndrome is less common among black children.

Sex

Fibromyalgia syndrome is diagnosed more commonly in girls than in boys. Studies show that girls are at least 3-7 times more likely than boys to be diagnosed with fibromyalgia syndrome.

Age

Patients with pediatric fibromyalgia syndrome most frequently present in adolescence (age 13-15 y). The earliest reported case in pediatrics was a 5-year-old child with fibromyalgia syndrome.

Clinical

History

Fibromyalgia syndrome (FMS) is characterized by musculoskeletal pain, stiffness, and aching. The severity of pain at the tender points (TPs) rates 8 on a scale of 10. Symptoms of fatigue, anxiety, and depression are reported. Adolescents with fibromyalgia syndrome often describe abnormal sleep patterns that interfere with school and family activities. Descriptions of difficulty falling asleep, frequent awakenings due to discomfort, and feeling unrested in the morning are common. The Yunis and Masi criteria for juvenile primary fibromyalgia syndrome (JPFS) state that the child experiences 3 of 10 minor criteria, most of which are subjective findings reported by the child.

The 10 minor criteria are as follows (note that criteria 1-10 are subjective symptom reports):³

1. Fatigue
2. Sleep disturbance
3. Chronic anxiety or tension
4. Chronic headaches
5. Irritable bowel syndrome symptoms
6. Subjective soft tissue swelling
7. Numbness or tingling of the extremities
8. Pain modulated by stress or anxiety
9. Pain modulated by weather
10. Pain modulated by physical activity

Questions for patient and family should explore the presence of the following:

• Widespread pain or aching
• Headaches
• Morning stiffness and fatigue
• Subjective joint swelling
• Abdominal pain
• Symptoms of depression
• Quality and amount of sleep

Assess the quality of pain (eg, when, what, where, how long) with the following questions:

• When did the pain start?
• What makes it better?
• What makes it worse?
• What is it like (eg, sharp, dull, aching, deep)?
• What is the appearance of the affected area (eg, swelling, edema)?
• Where is the pain?
• How long does it last?
• Does it vary throughout the day?
• Does it wake you up at night?

Other questions about associated symptoms include the following:

• Do the child's legs move constantly during the night?
• Do you experience migraines or headaches?
• Do you have facial pain?
• Do you have fever?
• Do you have any change in appetite?
• Have you lost weight?
• Can you describe your sleep pattern?
• Are you disturbed easily during sleep?
• Do you have frequent awakenings?
• Do you feel rested in the morning?
• Do you have any bowel or GI symptoms?
• Do you feel anxious, sad, or depressed?
• Are your muscles weak?

Questions about the psychosocial aspect include the following:

• Are you experiencing any stressors or problems at school?
• Are you experiencing any stressors or problems in your family?
• Are you tired in school?
• Are you able to keep up with the other children at school and outside activities?
• What impact has the pain had on routine activities?
• How has your family responded to the pain?
• Does anyone at home have similar problems?

Common aggravating factors of fibromyalgia syndrome include the following:

• Anxiety and stress
• Cold weather
• Humid weather
• Inactivity
• Physical overactivity
• Poor sleep

Common alleviating factors of fibromyalgia syndrome include the following:

• Hot shower or bath
• Moderate activity
• Stretching and exercising
• Warm weather
• Massage

Physical

• Perform thumb palpitation of 18 specific TP sites with a force of 4 kg per unit area. This force is approximately the pressure necessary to blanch the examiner's nail. Note that this criterion is suggested but not agreed on among practitioners. Neumann et al suggest using a 3-kg criterion rather than 4 kg in children because their threshold is different from that in adults.¹⁴ In the child, palpation elicits tenderness in TPs at 5 of 11 of the following locations (note that most locations are bilateral):
  • Occiput - Bilateral, at the suboccipital muscle insertions
  • Low cervical - Bilateral, at the anterior aspects of the intertransverse spaces at C5-C7
  • Trapezius - Bilateral, at the mid point of the upper border
  • Supraspinatus - Bilateral, at origins, above the scapula spine near the medial border
  • Second rib - Bilateral, at the second costochondral junctions just lateral to the junctions on upper surfaces
  • Lateral epicondyle of humerus - Bilateral, 2 cm distal to the epicondyles
  • Gluteal - Bilateral, in upper outer quadrants of buttocks in anterior fold of muscle
  • Greater trochanter - Bilateral, posterior to the trochanteric prominence
  • Knee - Bilateral, at the medial fat pad proximal to the joint line
• In 1986, Calabro described that the examination of joints in juvenile fibromyalgia syndrome revealed normal findings despite tenderness and spasms in soft tissue on palpation.¹⁵ Therefore, classic signs of joint swelling, heat, or redness are not seen on examination. Physical findings to explore include joint hypermobility using criteria developed by Carter and Wilkerson and modified by Bird, swelling or joint edema, abdominal tenderness, and joint range of motion to determine stiffness. Skin palpation may also reveal changes in the texture of both skin and subcutaneous tissue.

Causes

Fibromyalgia syndrome is a physiologic entity rather than a psychiatric disorder. Yunus suggests that fibromyalgia is a part of a classification of disorders called central sensitivity syndromes (CSSs) that result from changes in the CNS.⁴ Neurochemical pathology of the CNS (spinal cord and brain) causes areas of the body to become sensitized such that pain is experienced from even mild touch or pressure. The underlying concept of CSS is that the 13 disorders have some similar clinical features and a common pathophysiological component of central sensitization (CS). Yunus disputes that the pain and suffering that people with the CSS disorders experience are merely psychiatric, psychosocial, or psychological in nature, as has often been thought in the past.⁴
 
The physiology of CS involves a process in which inflammation that may be caused by a minor trauma sets off an involved CNS response that results in pain and distress. The response pathway starts with the initial input that causes the release of bradykinin, prostaglandins, serotonin, and substance P to then activate A-delta and C-fiber nociceptors at peripheral tissues.⁴ Nociceptive impulses travel through fibers to wide dynamic range neurons in the spinal cord. At nerve terminals, activated C-fibers convey neurotransmitters or neuromodulators that barrage impulses at the synapse and hyperexcite postsynaptic receptors. The changes cause hyperexcitability escalation of other neurons, giving rise to hypersensitivity to peripheral stimuli.⁴
 
The enhanced nociceptive (spinal) flexion reflex (NFR) is a consistent objective test for CS obtained by electrically stimulating the sural nerve and then measuring the electromyelographic (EMG) response of the biceps femoris. People with fibromyalgia or other CSSs, have demonstrated an accentuated NFR (or decreased stimulus threshold) which is indicative of CS.⁴
 
Other physiologic aspects of CSS diseases include sympathetic overactivity, genetic factors, neuroendocrine dysfunctions, peripheral nociception generators (eg arthritis), environmental stimuli, poor sleep, viral or local infections (may trigger inflammatory mediators that activate nociceptive fibers), nonrestorative sleep, and psychosocial distress.^5,4

Proposed members of the CSS family include the following:^4,5

• Fibromyalgia syndrome
• Chronic fatigue syndrome
• Irritable bowel syndrome
• T-T headache (tension type)
• Migraine
• Temporomandibular disorders
• Myofascial pain syndrome
• Female urethral syndrome/interstitial cystitis
• Multiple chemical sensitivity syndrome
• Restless leg syndrome
• Periodic limb movements in sleep (PLMS)
• Primary dysmenorrhea
• Posttraumatic stress disorder

• Search for CME/CE on This Topic »

• Fibromyalgia (Physical Medicine and Rehabilitation)
• Fibromyalgia (Rheumatology)
• Chronic Pelvic Pain (Obstetrics and Gynecology)
• Chronic Pain Syndrome (Physical Medicine and Rehabilitation)

• Back, Ribs, Neck, and Head Center
• Fibromyalgia Causes
• Fibromyalgia Symptoms
• Chronic Pain
• Chronic Fatigue Syndrome Overview
• Fibromyalgia Overview
• Fatigue Overview
• Muscle Disorders Center
• Mental Health and Behavior Center
• Fibromyalgia Treatment

• Sodium Oxybate Reduces Fibromyalgia Pain and Fatigue
• Opioids Widely Used for Fibromyalgia Despite Absence of Efficacy Proof
• Neurologic Findings Are Common in Fibromyalgia Patients

• An Update on Fibromyalgia Syndrome: The Multimodal Therapeutic Approach
• Management of Chronic Nonmalignant Pain with Nonsteroidal Antiinflammatory Drugs
• The Use of Antidepressants for Chronic Pain

• Fibromyalgia Resource Center