Treatment Refractory Brachioradial Pruritus Treated with Topical Amitriptyline and Ketamine

Abstract

Brachioradial pruritus is an uncommon chronic neurocutaneous condition that often presents as extreme itching, burning or tingling on the dorsolateral aspect of the arm. The lack of primary skin lesions in brachioradial pruritus in addition to its poorly established pathophysiology can often lead to both diagnostic and therapeutic challenges for many physicians. Here, we present a case of brachioradial pruritus and the unique combination of topical amitriptyline and ketamine as an effective therapy, including a brief review of the literature on similar such cases.

Neuropathic agents in the management of pruritus in burn injuries: a systematic review and meta-analysis

“…This systematic review also limited the interventions being investigated to those drugs listed by NICE for the management of neuropathic pain. Despite this wide inclusion criteria including multiple drugs and drugs classes, the literature search did not return any information on therapies such as other tricyclic antidepressants, including amitriptyline, or selective serotonin reuptake inhibitors that have been used to manage pruritus in other conditions 76 77. Other therapies beyond pharmacological management may be of benefit in pruritus, namely, psychotherapy such as cognitive behavioral therapy, transcutaneous electrical nerve stimulation, and acupuncture.…”

Brachioradial pruritus in a 52-year-old woman: A case report

“…Of note, however, is that the patient had not been treated with systemic anti-depressants prior to this. This does present an interesting approach, sparing the patient systemic medical treatment [6]. However, given the overall safety of antidepressants and neuropathic agents, we believe physicians should consider this approach if more conventional treatments have failed.…”

The Role of Psychiatric, Analgesic, and Antiepileptic Medications in Chronic Pruritus

“…TCAs also exert an inhibitory effect on cholinergic, muscarinic, and histamine receptors, which have antinociceptive properties. The antihistamine and anticholinergic action of antidepressants may also facilitate pain signaling [ 15 ].…”

“…According to a systematic review of 19 clinical trials, topical doxepin given in low doses, defined as 10-100 mg, was effective in treating chronic pruritus [ 3 , 14 ]. In a case report on a patient with refractory brachioradial pruritus, a combination of topical amitriptyline and ketamine proved effective [ 15 ].…”

“…Pruritus relief by TCAs is hypothesized to occur through the inhibition of 5-HT and norepinephrine reuptake on cutaneous nerves. This reduces the sensation of itch, more specifically the burning and tingling symptoms [ 15 ]. Given the established use of TCAs for peripheral neuropathy, this seems to be a logical explanation for its mechanism of action.…”