Vasculitis and the peripheral nervous system.

Peripheral neuropathy is a common feature of systemic vasculitis and can also occur when vessel wall inflammation is confined to the vasa nervorum, as a tissue-specific condition-non-systemic vasculitic neuropathy (NSVN). Typically, the clinical picture in both systemic and non-systemic cases is of a lower limb predominant, distal, asymmetric or multifocal neuropathy, which is painful and subacute in onset. For NSVN, nerve biopsy is required to make the diagnosis, and nerve biopsy also has a role when vasculitic neuropathy is suspected and a systemic process has not yet declared itself. Early recognition of the disorder is important, because it is treatable, and without treatment potentially disabling, or even lethal if part of an undiagnosed systemic process. Treatment is generally with combination therapy (glucocorticoid plus other immunosuppressant), after which motor and sensory recovery are likely to occur, albeit slowly, but the patient may be left with chronic neuropathic pain.