Neuropathic itch treated with oral cannabinoids: A case series

Abstract

CB: cannabinoid NRS: numerical rating scale VAS: visual analog scale INTRODUCTION Neuropathic pruritus is defined as an itch arising from diseases of the central or peripheral nervous system, including nerve damage, compression, or irritation. It can be generalized or localized and is encompassed within a broad range of diagnoses, including notalgia paresthetica, brachioradialis pruritus, certain forms of vulvar itch, and small fiber neuropathy, amongst others. Brachioradial pruritus is a well-known type of neuropathic itch that is believed to result from an insult to cervical nerves C5-C8 from degenerative disc disease or trauma. Symptoms include itch, burning, numbness, and tingling affecting the dorsolateral aspects of the upper extremities. Although most cases of vulvar itch can be attributed to infectious causes or inflammatory dermatoses, such as psoriasis, lichen simplex chronicus, lichen sclerosus, or contact dermatitis, some cases of chronic vulvar itch can be categorized under the umbrella of genitofemoral neuralgia or vulvodynia. Classically regarded as a type of neuropathic pain, itch and burning can accompany vulvodynia in 20% and 70% of cases, respectively, and are similarly addressed in the same way with medications targeting neurogenic pathways. In many cases of localized neuropathic itch, treatment can be challenging because topical therapies are limited and systemic treatments may provoke many side effects. Treatment options for neuropathic itch typically include topical local anesthesia, capsaicin formulations, calcineurin inhibitors, menthol or camphor, and systemic approaches with gabapentinoids, selective serotonin