nerve damage, nerve compression, nerve irritation” ( Ständer et al. Etiology Category III (NI) is defined as “arising from diseases or disorders of the central or peripheral nervous system, e.g. The International Forum for the Study of Itch (IFSI) recognizes four types of itch causality-dermatologic, systemic, neurologic, and psychiatric ( Ständer et al. At a practical level, NI can only be diagnosed after dermatological and systemic causes have been excluded, so dermatological evaluation should usually precede referral to a neurologist. In other words, there is uncoupling of the stimulus-response curve for itch sensation since dysfunction or disease of itch-signaling neurons is causing them to fire without cause.

NI is thus defined as perception of itch in the absence of pruritogenic stimuli (formerly known to dermatologists as pruritus sine materia).

The epistemology of neuropathic itch (NI) is based on that of neuropathic pain, which has so far worked well, no doubt because most peripheral itch neurons are a subset of peripheral pain neurons.

Rash that itches then hurts