(140) Successful Treatment of Excoriation Disorder with IV N-Acetylcysteine

Abstract: Background: Excoriation Disorder (ED) entails compulsive manipulation of skin with tissue damage. No consensus exists around optimal treatment (Lochner, 2017), and while case reports and clinical trials demonstrate efficacy and safety of oral n-acetylcysteine (NAC), intravenous NAC’s efficacy has not been explored as thoroughly. NAC increases extracellular concentrations of glutamate in the nucleus accumbens, thus inhibiting further presynaptic release of glutamate (Grant, 2016). This may normalize dysregulated glutamate in compulsive disorders. We report a case suggesting intravenous administration of NAC may be effective in treating ED.

Case Report: A 38-year-old woman with tobacco, cannabis, and MDMA use, MDD, GAD, PTSD, and 8 years of ED was admitted to the medicine service following an argument with her fiancé and overdose on baclofen and acetaminophen. She reported that ED-related scarring caused pain and impacted self-esteem.

Upon hospital day (HD) 1, she received 150mg/kg IV NAC for acetaminophen overdose. Initial dose of 14.97g was followed by additional doses of 4.99g and 9.98g. On HD2 and HD3, a steady dose of 9.07g IV NAC per day was administered and family support increased. By HD4, she described decreased skin-picking. Escitalopram 10mg PO daily was started on HD5. Mindfulness-based and psychotherapeutic interventions for depression and ED were introduced on HD6 and 7. NAC 600mg capsules PO once daily were initiated for ED on HD7. She reported mindfulness techniques helped manage skin-picking urges and was transferred to the psychiatric unit on HD7. On HD10, depression and skin-picking remained absent. She was discharged on oral NAC 600mg daily, escitalopram 20mg daily, hydroxyzine 25mg as needed, and ferrous sulfate 325mg.

Discussion: After IV NAC, ED improved prior to initiating escitalopram and antihistamines, suggesting that high dose IV NAC effected rapid resolution. Improvement in depression due to increased social support may have also improved or attenuated symptoms. IV NAC is safe, inexpensive, readily available inpatient, and requires little expertise to administer. Psychiatric patients already routinely receive interventional procedures such as ECT, TMS, and ketamine infusions. If further research demonstrates efficacy of IV NAC, it could be rapidly instituted on a large scale for ED.

Conclusion: High dose IV NAC may have contributed to the patient’s rapidly improved skin-picking prior to initiation of other psychiatric interventions. Future RCTs would help explore the efficacy of high doses of NAC alone and in combination with psychotherapy and SSRIs.

References:

Grant, J. E., Chamberlain, S. R., Redden, S. A., Leppink, E. W., Odlaug, B. L., & Kim, S. W. (2016). N-Acetylcysteine in the Treatment of Excoriation Disorder: A Randomized Clinical Trial. JAMA psychiatry, 73(5), 490–496.



Lochner, C., Roos, A., & Stein, D. J. (2017). Excoriation (skin-picking) disorder: a systematic review of treatment options. Neuropsychiatric disease and treatment, 13, 1867–1872.