Chronic primary and secondary pain in children: SAQ

Question 1 (10 marks)

Using the ICD-11 chronic pain classification and the mechanism of central sensitisation, explain how you frame this girl's problem, and justify why her normal investigations are consistent with, rather than contradictory to, her pain. [1]

A full-mark answer defines chronic pain, places the case in chronic primary pain, names the nociplastic mechanism and central sensitisation, and explains why a normal scan does not refute the pain. [2]

Definition and classification (3 marks). Chronic pain is defined as pain persisting or recurring for more than three months. Under ICD-11, this girl has chronic primary pain, coded MG30.0: pain in one or more regions for more than three months, associated with significant emotional distress and significant functional disability, that is not better explained by another chronic pain condition. The pain moving between sites, the disability reflected in school absence, and the normal screen together place her squarely in the primary, nociplastic group rather than a secondary category such as secondary musculoskeletal or cancer-related pain. [1][2]

The mechanism (3 marks). Chronic primary pain is nociplastic, arising from altered nociceptive function in a structurally intact nervous system. The core mechanism is central sensitisation: after prolonged nociceptive input, the spinal cord and brain become more responsive, the threshold for a stimulus to register as pain drops, and mildly unpleasant stimuli become painful. This is a real biological change in how the nervous system processes signals, not a psychological invention, and it explains why the pain is widespread, fluctuating and migrating. [1]

Why the normal investigations are consistent (2 marks). Nociplastic pain is generated by altered nervous-system function without ongoing tissue damage, so a normal magnetic resonance image and normal blood tests are exactly what is expected. The error is to read a normal scan as evidence the pain is not real; the correct reframe is that the tests exclude dangerous disease and confirm that the problem is a sensitised nervous system that can be retrained. [7]

The fear-avoidance cycle (2 marks). The withdrawal from sport, the broken sleep and the school avoidance describe the behavioural counterpart: the child interprets pain as damage, fears movement, avoids activity, becomes deconditioned, and hurts more when she does move, which confirms the belief that movement is dangerous. Naming this cycle is what makes a graded reactivation plan credible to the family. [7]

Question 2 (10 marks)

Describe the biopsychosocial assessment and red-flag screen you would perform, and outline the interdisciplinary rehabilitation plan you would build, including your advice to the family on opioids. [7]

A full-mark answer covers the seven biopsychosocial domains, the red-flag screen, the three-pillar rehabilitation plan with function as the goal, and the opioid advice, with appropriate citations. [9]

Biopsychosocial assessment (3 marks). Cover seven domains: the pain itself (site, character, course, triggers, relievers); mood and anxiety; sleep; school attendance and activity; the family response and family pain history; prior investigations and treatments; and the child's own understanding and goals. Examine to screen for the serious mimics (growth, pubertal staging, a full musculoskeletal and neurological screen) and to demonstrate a thorough examination. Quantify function with a numeric pain scale, a Functional Disability Inventory, a pain and sleep diary, and a direct count of school days missed. Assess parental catastrophising and over-protection, which are powerful maintainers of disability. [7]

Red-flag screen (2 marks). Actively seek the features that would demand investigation before a primary pain diagnosis: weight loss, night pain that wakes her from sleep, persistent fever or fatigue out of proportion, neurological signs, bowel or bladder dysfunction, and raised inflammatory markers. Their absence, with the documented normal screen, supports the primary pain diagnosis; their presence would mandate further investigation for malignancy, inflammatory disease, infection or structural neurological disease. [7]

The rehabilitation plan (3 marks). Build an interdisciplinary plan with a paediatrician, psychologist, physiotherapist and nurse or social worker, with the school and family engaged. State the goal up front: restored function, sleep, mood, school attendance and participation, not a pain score of zero. Pillar one is graded physical reactivation with pacing, a sleep and routine plan, and a staged return to school. Pillar two is psychological therapy, principally cognitive behavioural therapy or acceptance and commitment therapy, which has the strongest evidence of any intervention in paediatric chronic pain, with parent-focused strategies. Pillar three is judicious, mechanism-based pharmacology: limited to short-term nociceptive adjuncts such as paracetamol or non-steroidal anti-inflammatories for genuine flares, and gabapentinoids or tricyclics for any neuropathic component; nociplastic pain responds poorly to analgesics. [7][9]

Opioid advice (2 marks). Advise the family that opioids are not recommended for chronic primary, non-cancer pain in children: the WHO 2020 guidelines do not recommend initiating strong opioids for chronic primary pain, the evidence for efficacy is absent, and the harms include dependence, adverse effects and lost function. If she is not already on an opioid, none should be started; if she were, the plan would include supervised deprescribing as part of rehabilitation. Reframe the request for stronger painkillers into the recovery plan of movement, sleep, mood and school. [7]