How common is pain in juvenile idiopathic arthritis?

Pain is the most common and distressing symptom experienced by children and adolescents with juvenile idiopathic arthritis (JIA). In a longitudinal study of polyarticular arthritis, N = 41 patients (aged 8–18 years) completed daily paper diaries over an 8-week period to report daily symptoms and function . On average, patients reported the presence of pain on 73% of days, with most patients reporting pain on more than 60% of days. The average number of painful joints reported on pain days was 8.1 ± 12.6. A significant proportion of patients (39%) reported the experience of pain on all diary days, while a minority (5%) reported no pain over the study period. The average pain intensity was in the mild range (36.6 ± 24.5 on a 100-point scale), although a sub-group of participants (31%) reported average pain intensity greater than 40 . More recently, a sample of N = 76 patients with JIA (aged 9–17 years) completed electronic pain diaries three times per day over a 2-week period . On average, participants reported pain intensity (21.7 ± 20.1), unpleasantness (19.8 ± 19.5), and interference (13.4 ± 15.2) in the mild range on a 100-point scale. Pain was found to interfere most with walking ability, and was also associated with symptoms of stiffness (24.4 ± 23.2) and mild to moderate fatigue (36.6 ± 24.1) . Recently, Kimura and colleagues surveyed North American pediatric rheumatologists to assess current practices regarding treatment of chronic arthritis pain . The sample included N = 53 pediatric rheumatologists with an average of 14.0 ± 7.7 years in practice. Overall, 77% of respondents agreed that there are pediatric patients who continue to experience moderate to severe pain despite adequate treatment with disease-modifying therapy and non-steroidal anti-inflammatory drugs . These findings are supported by a recent electronic diary study by Bromberg and colleagues where a sample of 59 JIA patients aged 8–18 years completed an e-diary three times per day for one month . Although most participants were under treatment with a disease-modifying anti-rheumatic drug (79%) or a biologic agent (47%), patients continued to report pain in 66% of all e-diary entries. Across the entire study period, not one participant was completely pain-free, and 86% of participants reported at least one high pain level . Several studies have also reported reduced pain thresholds and reduced pain tolerance in patients with JIA, including those with active and quiescent disease . These lowered pain thresholds and tolerance have been correlated with increased reported pain, suggesting a role for central sensitization and nociceptive pathway plasticity in JIA .

How does pain affect health-related quality of life?

Pain is known to negatively impact all aspects of health-related quality of life (HRQL). In a study involving N = 59 patients (aged 8–18 years) and their parents, Sawyer and colleagues found that children and adolescents with JIA experienced significantly more problems with physical, emotional, social, and school functioning than healthy individuals . Furthermore, reports from parents and children showed that higher pain levels were associated with more impairment in physical, emotional, and social functioning. In a larger study involving N = 308 adolescents with JIA aged 11, 14, and 17 years, Shaw and colleagues found that HRQL scores were less than optimal, particularly related to gross motor functioning (e.g. kneeling, standing, running) and systemic functioning (e.g. stiffness, joint tenderness, tiring easily, joint swelling) . Lower scores for HRQL were consistently related to greater levels of disability, worse pain, and greater joint involvement. Furthermore, adolescents who were most likely to rate frustration or depression as one of their biggest problems were those with worse pain . In the survey of pediatric rheumatologists conducted by Kimura and colleagues, 98.1% of respondents agreed that there is a strong relationship between pain and perceived quality of life for children and adolescents with arthritis .

How does pain affect sleep?

Poor sleep and fatigue are other important consequences associated with arthritis pain. In a cross-sectional study involving N = 155 patients (aged 8–16 years) with JIA or juvenile dermatomyositis, all participants experienced moderately severe fatigue, and 44% reported sleep disturbances . Increased pain was associated with more sleep disturbance, more fatigue, and decreased quality of life. A recent systematic review of sleep in pediatric pain populations identified 9 JIA studies with a total of N = 310 patients . Overall, findings from behavioural measures and polysomnography demonstrated that children with persistent pain have significantly more sleep disturbances, including lower sleep efficiency, than healthy individuals. Sleep problems were also linked with impaired executive functioning. Specifically, more night awakenings predicted poorer rapid visual processing and higher apnea severity scores predicted longer reaction times. The authors of this systematic review concluded that, “… children with persistent pain commonly suffer from disturbed sleep, which puts them at risk for poor functional outcomes” (p. 126) .

What is the patient experience of living with arthritis pain?

It is important to consider the perspective of patients to better understand the impact of living with JIA. Tong and colleagues recently completed a systematic review of qualitative studies, which included 27 studies of N = 542 patients with JIA (aged 6–30 years) . One of the major themes identified across all studies was an aversion to being different. Specifically, patients described the presence of unrelenting and unpredictable pain as a major disruptor to their sense of normalcy compared with healthy peers. They also described the experience of disablement due to restrictions on their physical, social, and school activities. These impairments had a negative impact on emotional functioning, such as feelings of powerlessness and sadness. Another major theme discussed by patients was the stigma and misunderstanding associated with JIA, including frustration at the ‘invisible’ nature of arthritis pain and the unpredictability of symptom flares. The authors of this systematic review concluded, “JIA can have a debilitating impact on children and adolescents. Patients must contend with unpredictable phases of incapacitating pain, stigmatization, and physical limitations” (p. 1403) .

What are the long-term consequences of arthritis pain?

In terms of long-term impact, Packham and Hall followed-up on functional outcomes of adults with long-standing JIA (average disease duration of 28.3 years ± 10.8) . A total of N = 246 adults took part in an interview, clinical examination, and notes review, while N = 231 of these individuals completed a comprehensive functional and psychosocial questionnaire. The mean patient age was 35.4 years ± 11.1 at the time of the study, and average age at disease onset was 7.1 years ± 4.5. Overall, 24.5% of study participants had moderate clinical inflammation, while 18.8% had severe inflammation. Similarly, 54.4% had active arthritis according to laboratory tests (elevated C-reactive protein). A total of 42.9% of patients were characterized by severe disability across all disease subtypes. Severe disability was most common among individuals with systemic onset JIA (62.5%) and seronegative polyarticular JIA (50%), while oligoarticular (0%) and enthesitis-related JIA (16.1%) were associated with less functional impairment. In terms of emotional impact, a significant proportion of participants had high anxiety levels (31.6%) or had suffered from significant depression in the past (21.1%). Most participants continued to experience persistent pain from their arthritis, with 25% reporting pain intensity between 26 and 50 (100-point scale) and 32.9% reporting severe pain scores greater than 50. Only 7% of participants were pain-free at the time of assessment. The mean reported pain score across all participants was 37. Perceived level of control over pain was ‘poor or very poor’ in 22.8% of participants and ‘moderate’ in 45.2% of the sample. The authors of this study concluded, “adults with JIA often have significant levels of disability, usually related to severe continuing active disease over a prolonged period” (p. 1435) .

Section summary

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  Pain is the most frequent and distressing symptom associated with JIA.

  
  
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  Intensity is typically reported in the mild to moderate range, although severe pain is experienced in a smaller sub-group during disease flares .

  
  
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  Many patients continue to experience moderate to severe pain despite adequate treatment with disease-modifying therapy, biologics, and non-steroidal anti-inflammatory drugs .

  
  
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  Pain patterns can be unpredictable, with fluctuations within and between days .

  
  
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  Pain is associated with impairment of physical, emotional, social, and role functioning as well as sleep disturbances and fatigue .

  
  
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  About half of pediatric patients will continue to have active disease into adulthood, including symptoms of pain .

Pain as a multidimensional experience within a biopsychosocial model

Clinical rheumatologists are frequently challenged to assess and manage the pain of children and adolescents with rheumatic disease . In the context of assessment, it is critical to consider pain as a multidimensional experience that is comprised of sensory, affective, and evaluative components . The sensory dimension of pain is related to quality (what pain feels like), intensity (how much pain hurts), location (spatial distribution of pain), and duration (how long pain lasts). The affective dimension is related to the emotional impact of pain, such as the extent to which pain is perceived as unpleasant or distressing. The evaluative dimension describes the degree to which pain is perceived to interfere with physical, psychological, role, and social functioning.

The multidimensional nature of pain is best considered within the context of a biopsychosocial model, which encompasses biological, environmental, and cognitive-behavioural mechanisms. As described by Anthony and Schanberg (2005), the development and maintenance of a child’s arthritis pain experience is influenced by an interaction of: (1) biological factors such as genetics, disease activity, abnormal pain processing, and medications; (2) environmental factors such as parent pain history, parent coping and adjustment, family relationships, as well as school and social relationships; (3) cognitive-behavioural factors such as stress, mood, psychological adjustment, pain coping skills, and self-efficacy . Importantly, several studies have demonstrated that disease activity (e.g. physician global assessment scores) typically accounts for only a small proportion (6.5–28%) of variance in reported pain . Other factors that influence pain perception include patient age, developmental status, coping ability, mood, stress levels, as well as family and environmental factors . Thus, an understanding of the many interconnected factors that may contribute to a patient’s pain experience can enhance the ability of clinicians to manage pain using multimodal approaches, including pharmacological, physical, and psychological strategies . Importantly, the failure to recognize and manage potential contributing factors to pain, such as poor sleep, anxiety, social isolation, and inactivity can lead to a cycle of pain and maintenance of symptoms .

Pain assessment as a cornerstone of pain management

It is well recognized that pain assessment is the first step in the effective management of pain. To treat pain effectively, an ongoing assessment of the severity and impact of pain and the patient’s response to treatment is essential for disease management. Pain measurement typically refers to a quantification of pain intensity (for example, ‘how much does it hurt?’) . In contrast, pain assessment involves a comprehensive characterization of the pain experience by using clinical judgement to consider the nature, significance, and context of a patient’s pain . The importance of pain assessment as a cornerstone of disease management has been recognized by a working group of representatives from the American College of Rheumatology, American Academy of Pediatrics, American Board of Pediatrics, and Association of Rheumatology Health Professionals . This working group established a set of quality measures for the assessment of the process of care in JIA. Specifically, this group recommended that, “pain should be assessed in all patients at the first visit [to a pediatric rheumatologist after a diagnosis has been made] and at each subsequent visit that occurs at least 7 days apart” (p. 13) . The group also emphasized that pain must be assessed using valid and reliable tools that are developmentally appropriate for the individual patient.

Sources of pain assessment data

Patient self-report is a key source of data for the assessment of pain in pediatric patients who are cognitively able to describe their pain experience. Research suggests that chronological age is the best predictor of whether an individual patient is able to accurately self-report their pain . As described by von Baeyer (2006), most children aged 5 years and older are able to self-report their current pain when provided with a developmentally appropriate tool . For children younger than 5 years and/or patients with cognitive impairment or communication difficulties, an observational pain measure should be utilized . In all cases, patient self-report of pain should be considered alongside knowledge of the clinical context, the patient’s current state, as well as behavioural observation . The same pain scale should also be used for individual patients over time in order to generate consistent data for longitudinal comparison across the trajectory of disease management.

Practical issues to consider when assessing pain using self-report scales

The issues are discussed in Table 1 .

Section summary

• •
  

  The assessment of pain is a cornerstone of disease management for children and adolescents with arthritis .

  
  
• •
  

  Pain is a multidimensional experience that should be considered in the context of a biopsychosocial model .

  
  
• •
  

  Pain should be assessed frequently and consistently by clinical rheumatologists throughout the disease management process using valid and reliable measures .

  
  
• •
  

  Patient self-report is a key source of pain information and should be considered alongside knowledge of clinical context, patient narrative, and behavioural observation .

  
  
• •
  

  Most children aged 5 years and older are able to self-report their current pain when provided with a developmentally appropriate tool .

  
  
• •
  

  For children younger than 5 years and/or patients with cognitive impairment or communication difficulties, an observational pain tool should be used .

Pain as a multidimensional experience within a biopsychosocial model

Clinical rheumatologists are frequently challenged to assess and manage the pain of children and adolescents with rheumatic disease . In the context of assessment, it is critical to consider pain as a multidimensional experience that is comprised of sensory, affective, and evaluative components . The sensory dimension of pain is related to quality (what pain feels like), intensity (how much pain hurts), location (spatial distribution of pain), and duration (how long pain lasts). The affective dimension is related to the emotional impact of pain, such as the extent to which pain is perceived as unpleasant or distressing. The evaluative dimension describes the degree to which pain is perceived to interfere with physical, psychological, role, and social functioning.

The multidimensional nature of pain is best considered within the context of a biopsychosocial model, which encompasses biological, environmental, and cognitive-behavioural mechanisms. As described by Anthony and Schanberg (2005), the development and maintenance of a child’s arthritis pain experience is influenced by an interaction of: (1) biological factors such as genetics, disease activity, abnormal pain processing, and medications; (2) environmental factors such as parent pain history, parent coping and adjustment, family relationships, as well as school and social relationships; (3) cognitive-behavioural factors such as stress, mood, psychological adjustment, pain coping skills, and self-efficacy . Importantly, several studies have demonstrated that disease activity (e.g. physician global assessment scores) typically accounts for only a small proportion (6.5–28%) of variance in reported pain . Other factors that influence pain perception include patient age, developmental status, coping ability, mood, stress levels, as well as family and environmental factors . Thus, an understanding of the many interconnected factors that may contribute to a patient’s pain experience can enhance the ability of clinicians to manage pain using multimodal approaches, including pharmacological, physical, and psychological strategies . Importantly, the failure to recognize and manage potential contributing factors to pain, such as poor sleep, anxiety, social isolation, and inactivity can lead to a cycle of pain and maintenance of symptoms .

Pain assessment as a cornerstone of pain management

It is well recognized that pain assessment is the first step in the effective management of pain. To treat pain effectively, an ongoing assessment of the severity and impact of pain and the patient’s response to treatment is essential for disease management. Pain measurement typically refers to a quantification of pain intensity (for example, ‘how much does it hurt?’) . In contrast, pain assessment involves a comprehensive characterization of the pain experience by using clinical judgement to consider the nature, significance, and context of a patient’s pain . The importance of pain assessment as a cornerstone of disease management has been recognized by a working group of representatives from the American College of Rheumatology, American Academy of Pediatrics, American Board of Pediatrics, and Association of Rheumatology Health Professionals . This working group established a set of quality measures for the assessment of the process of care in JIA. Specifically, this group recommended that, “pain should be assessed in all patients at the first visit [to a pediatric rheumatologist after a diagnosis has been made] and at each subsequent visit that occurs at least 7 days apart” (p. 13) . The group also emphasized that pain must be assessed using valid and reliable tools that are developmentally appropriate for the individual patient.

Sources of pain assessment data

Patient self-report is a key source of data for the assessment of pain in pediatric patients who are cognitively able to describe their pain experience. Research suggests that chronological age is the best predictor of whether an individual patient is able to accurately self-report their pain . As described by von Baeyer (2006), most children aged 5 years and older are able to self-report their current pain when provided with a developmentally appropriate tool . For children younger than 5 years and/or patients with cognitive impairment or communication difficulties, an observational pain measure should be utilized . In all cases, patient self-report of pain should be considered alongside knowledge of the clinical context, the patient’s current state, as well as behavioural observation . The same pain scale should also be used for individual patients over time in order to generate consistent data for longitudinal comparison across the trajectory of disease management.

Practical issues to consider when assessing pain using self-report scales

The issues are discussed in Table 1 .

Section summary

• •
  

  The assessment of pain is a cornerstone of disease management for children and adolescents with arthritis .

  
  
• •
  

  Pain is a multidimensional experience that should be considered in the context of a biopsychosocial model .

  
  
• •
  

  Pain should be assessed frequently and consistently by clinical rheumatologists throughout the disease management process using valid and reliable measures .

  
  
• •
  

  Patient self-report is a key source of pain information and should be considered alongside knowledge of clinical context, patient narrative, and behavioural observation .

  
  
• •
  

  Most children aged 5 years and older are able to self-report their current pain when provided with a developmentally appropriate tool .

  
  
• •
  

  For children younger than 5 years and/or patients with cognitive impairment or communication difficulties, an observational pain tool should be used .