Battling Neuropathic Scar Pain With Botulinum Toxin

September 2019 | Volume 18 | Issue 9 | Case Reports | 937 | Copyright © September 2019


Andrew Schuler BS,ª Jesse Veenstra MD PhD,B David Ozog MDb

aUniversity of Michigan Medical School, Ann Arbor, MI 

BDepartment of Dermatology, Henry Ford Health System, Detroit, MI

DISCUSSION

negatively impact patients’ quality of life through cosmetic disfigurement, pain, itching, and restriction of mobility.9,10 Neuropathic pain in hypertrophic and keloid scars is partially mediated by neuropeptides like CGRP and substance P; recent data have implicated these neurotransmitters as a source of pain in normotrophic scars as well.1,11 Our case also illustrates that tension vectures from scar contracture may also play a role in persistent neuropathic scar pain.

Various therapies have been studied for the prevention and treatment of scars. Many trials have focused on improving cosmetic appearance and reducing symptoms in hypertrophic and keloid scars, but less emphasis has been placed on therapies for normotrophic scars. Current guidelines cite compression and occlusive therapy, intralesional steroids, cryotherapy, laser therapy and surgical excision as first-line therapies for treating keloid and hypertrophic scars.12,13 Emerging therapies continue to be studied, including 5-fluorouracil, imiquimod, tacrolimus, retinoic acid, and verapamil.13 BTA has been studied as a monotherapy for treatment of scars with promising results. Multiple, small randomized controlled trials have shown BTA to be as effective as intralesional steroid injections at reducing volume of hypertrophic scars, improving pliability, erythema and itching.14 Studies of postoperative scar prevention with BTA have also shown promise.15 Regarding neuropathic pain, only one study and several case reports have demonstrated pain reduction in scars after injection with BTA.4,6,7 A single case report also described a durable reduction in neuropathic scar pain after 1 treatment of BTA for a 6-month-old Mohs surgery scar.8 Our patient described a pins and needles sensation at her melanoma excision scar consistent with neuropathic pain, which was refractory to multiple other treatments. Given the successful use of BTA in conditions with neuropathic pain and the few reports of pain reduction in keloid and Mohs scars, we hypothesized that BTA injection may yield therapeutic benefit in our patient as well. Our patient had marked, durable reduction in scar pain symptoms after treatment, indicating that BTA may be a viable treatment for painful normotrophic scars. However, further studies are needed to help determine the efficacy of BTA in treating painful hypertrophic, keloid, and normotrophic scars.

DISCLOSURE

The authors have no relevant conflicts of interest.

REFERENCES

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AUTHOR CORRESPONDENCE

Jesse Veenstra MD PhD jveenst1@hfhs.org