Electrical neurostimulation for the treatment of chronic pruritus: A systematic review

Abstract

Approximately one fifth of the world population experiences continuous itch for 6 weeks or more during their life, that is chronic itch. It is diverse in its aetiologies, and it is notoriously hard to treat. Because itch and pain have largely overlapping pathophysiology and the demonstrated efficacy of neurostimulation in treatment of selected chronic pain conditions, we conducted a systematic review to investigate whether neurostimulation could be an effective treatment for chronic itch. We identified two randomized controlled trials and 17 open label studies or case reports investigating various neurostimulation modalities for the treatment of refractory itch of various aetiologies. Transcutaneous electrical nerve stimulation (TENS) was the most investigated modality (n = 17), and in the largest number of conditions. Other modalities were cutaneous field stimulation (n = 2), painscrambler (n = 1), transcranial direct current stimulation (n = 1) and peripheral nerve field stimulation (n = 1). Atopic dermatitis was the most studied condition (n = 5). Despite the large heterogeneity in used stimulation paradigms and outcome parameters, all studies reported a positive effect of at least one neurostimulation modality. Our review indicates that electrical neurostimulation could be considered for the treatment of refractory chronic itch of selected aetiologies, such as atopic dermatitis or burn pruritus. However, better understanding of the mechanisms of action of the neurostimulation modalities and regimens in various pruritic conditions is necessary.

Keywords: chronic pruritus; itch; neurostimulation; therapy.

FIGURE 1

Flowchart of study selection. † Congress abstracts (N = 5, Bruel 2013, Lang 2013, Ricciardo 2009, Orthman 2019, Carroll 2009). Only abstract available (N = 3, Fjellner 1978, Kilic Akca 2016, Duo 1987). Only title available (N = 1, Sequeira 2016). Duplicate (N=2, Wallengren 2004, Waked 2013). Erratum (latest version used) (N = 1, Yusek 2013). ‡ Experimentally induced itch (N = 3, Hill 2015, Nilsson 1996, Wallengren 2002). Primarily concerning pain (N = 1, Wang 2009). Letter to editor (N = 1, Tinegate 2002)