electrochemical skin conductance, an accurate objective technique, could be considered as a good screening tool to limit skin biopsy in patients in whom it is not suitable. Cause Central neuropathic pain is found in spinal cord injury, multiple sclerosis, Peripheral neuropathies are commonly caused by diabetes, metabolic disorders, herpes zoster infection, HIV-related neuropathies, nutritional deficiencies, toxins, remote manifestations of malignancies, immune mediated disorders and physical trauma to a nerve trunk. Neuropathic pain is common in cancer as a direct result of cancer on peripheral nerves (e.g., compression by a tumor), or as a side effect of chemotherapy (chemotherapy-induced peripheral neuropathy), radiation injury or surgery. Comorbidities Neuropathic pain has profound physiological effects on the brain which can manifest as psychological disorders. Rodent models where the social effects of chronic pain can be isolated from other factors suggest that induction of chronic pain can cause anxio-depressive symptoms and that particular circuits in the brain have a direct connection. Depression and neuropathic pain may have a bidirectional relationship and relief of co-morbid depression may underlie some of the therapeutic efficacy of antidepressants in neuropathic pain. Neuropathic pain has important effects on social well-being that should not be ignored. People with neuropathic pain may have difficulty working exhibiting higher levels of presenteeism, absenteeism and unemployment, exhibit higher levels of substance misuse (which may be related to attempted self-medication), and present difficulties with social interactions. Moreover, uncontrolled neuropathic pain is a significant risk factor for suicide. Certain classes of neuropathic pain may cause serious adverse effects necessitating hospital admission, for instance trigeminal neuralgia can present as a severe crisis where the patient may have difficulty talking, eating and drinking. As neuropathic pain may be comorbid with cancer, it can have important dose limiting effects on certain classes of chemotherapeutic. Treatments Neuropathic pain can be very difficult to treat with only some 40-60% of people achieving partial relief. General approach First line treatments are certain antidepressants (tricyclic antidepressants and serotonin–norepinephrine reuptake inhibitors), anticonvulsants (pregabalin and gabapentin). Opioid analgesics are recognized as useful agents but are not recommended as first line treatments. A broader range of treatments are used in specialist care. There are limited data and guidance for the long-term treatment of pain. Notably, strong evidence from randomized controlled trials is not available for all interventions. Primary interventions Anticonvulsants Pregabalin and gabapentin may reduce pain associated with diabetic neuropathy. The anticonvulsants carbamazepine and oxcarbazepine are especially