CIDP and other inflammatory neuropathies in diabetes - diagnosis and management

Distal symmetric polyneuropathy (DSPN) is the most common neuropathy to occur in diabetes mellitus. However, patients with diabetes can also develop inflammatory neuropathies, the most common and most treatable of which is chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Whether diabetes is a risk factor for CIDP remains under debate. Early studies suggested that patients with diabetes were at increased risk of CIDP, but epidemiological studies failed to confirm the association, and subsequent data have re-opened the debate. Inadequate interpretation of investigations and differentials between CIDP and other neuropathies that can occur in diabetes, such as DSPN, diabetic radiculoplexus neuropathies and vasculitic multiple mononeuropathy, might mean that CIDP is under-recognized. Despite a response rate of >80% to first-line therapies for CIDP in patients with or without diabetes, those with diabetes often present with greater disability owing to late referral and axonal pathology attributed to DSPN. The increasing worldwide prevalence of diabetes creates an urgent need to improve identification of potentially treatable neuropathies, such as CIDP. In this Review, we consider the features of CIDP in patients with diabetes, and discuss how these features can be used to differentiate the condition from other neuropathies. We also review the management options for CIDP and other inflammatory neuropathies in patients with diabetes.