The Investigators will determine whether a questionnaire to identify neuropathic pain in adults is also useful in children. This will help paediatricians and other doctors to recognise neuropathic pain and start appropriate treatment or know when to refer children to a chronic pain clinic.The Investigators will also measure the effects of neuropathic pain on mood, sleep, and quality of life (using questionnaires); identify changes in the sensitivity of the skin to touch and other sensations (using specialised sensory tests); and determine the feasibility of brain imaging for assessing changes in the brain (using magnetic resonance imaging or MRI), in children with neuropathic pain. This information will allow the investigators to measure how effective different types of treatment are, and help ensure children get the most appropriate treatment or interventions to reduce pain and effects on quality of life.