Chronic Pain in Peripheral Neuropathy

Neuropathic pain is common in patients with peripheral neuropathy. Highly prevalent conditions including polyneuropathy, radiculopathy, and mononeuropathy, and less prevalent conditions such as plexopathy and neuronopathy share pain as central aspect that often requires treatment. Diagnosis often requires only a careful clinical history, but this can be assisted by validated instruments to distinguish neuropathic from non-neuropathic causes (e.g., DN4) on the basis of pain quality as well as quantifying pain intensity (e.g., numerical rating scale and visual analog scale). Confirmatory testing is often not required, but skin biopsies for intraepidermal nerve fiber density have the best diagnostic characteristics for identifying structural injury to small fibers. Unfortunately, neuropathic pain is often under-recognized and undertreated. Guidelines based on systematic review of the literature have reached a consensus that tricyclic antidepressants (TCAs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and gabapentinoids are efficacious for the treatment of neuropathic pain. These drug classes show similar efficacy and tolerability; therefore, cost becomes an important consideration when determining which medication to prescribe first. Opioids have also demonstrated short-term efficacy, but long-term efficacy data is lacking along with mounting evidence of the harms of chronic opioids therapy. Non-pharmacologic interventions will likely be important to treat neuropathic pain given the low efficacy of pharmacologic approaches, but evidence to date is based on studies with methodologic limitations.