Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare neurological disorder in which there is inflammation of nerve roots and peripheral nerves and destruction of the fatty protective covering (myelin sheath) over the nerves. Neuropathic pain is a pain condition that's usually chronic. It's usually caused by chronic, progressive nerve disease, and it can also occur as a result of injury or infection. If you have chronic neuropathic pain, it can flare up at any time without an obvious pain-inducing event or factor.