BoNT-A Injection Shows Prolonged Efficacy in Patients With Nail Psoriasis, Study Finds

Botulinum toxin A (BoNT-A) injection emerged as an effective therapy for patients with nail psoriasis, showing sustained efficacy for up to 6 months with a single injection, according to one study.

Doctor treats nail psoriasis | Image Credit: fusssergei - stock.adobe.com

This randomized intraindividual comparative-controlled study is published in the Journal of the American Academy of Dermatology.¹

“To our knowledge, this study is the first randomized intra-individual controlled trial to demonstrate the efficacy of BoNT-A injection compared to intralesional steroid injection and the topical VitD [vitamin D]/steroid which are the first line of treatment for nail matrix and nail bed lesions in nail psoriasis,” wrote the researchers of the study.

Nail psoriasis remains a challenging condition to manage, with little satisfaction reported with current treatment. The treatment of nail psoriasis, which occurs in 50% to 79% of patients with psoriasis, is determined by several factors, including how many of the nails are affected, as well as the severity of disease and impact on quality of life, according to a 2022 study that examined management options for nail conditions.²

In the current study, the researchers aimed to compare the efficacy of BoNT-A injection, triamcinolone acetonide (TA) injection, topical combination of vitamin D/steroid (VitD/steroid), and placebo in improving nail psoriasis.¹

Patients received 4 distinct treatment modalities matched to each psoriatic nail. Each patient had at least 4 psoriatic fingernails and a target Nail Psoriasis Severity Index (NAPSI) score of at least 3 points per nail at baseline. Nails were randomly selected to receive intralesional BoNT-A injection at baseline, intralesional TA at baseline and at week 8, daily topical VitD/steroid application for 16 weeks, and placebo.

A total of 18 participants were initially included in the study, including a total of 72 fingernails. However, 2 patients discontinued treatment due to lack of follow-up and required systemic treatment from the worsening cutaneous psoriasis. Therefore, 16 patients and a total of 64 psoriatic nails completed the 24-week follow-up.

The mean age of patients was 45 (range, 30-71) years, with 75 male participants and 25 female participants. The mean (SD) Psoriasis Area and Severity Index score was 4.7 (2.1), patients had an average disease duration of 11 years, and the mean (SD) BMI score was within the overweight range at 26.9 (4.5).

At week 16, all 3 regimens showed significant nail improvement compared with baseline (P < .01). The total target NAPSI reached a nearly 40% reduction following a single BoNT-A injection (P = .008).

Additionally, the researchers observed a 50% reduction in the total target NAPSI with every 8-week injection of TA (P = .001) and roughly a 30% change with the combination of topical VitD/steroid (P = .003). Furthermore, the BoNT-A injection group showed continuous nail improvement at week 24, while the TA group remained stable.

The researchers acknowledged some limitations to the study, including having a relatively low number of participants, as well as a short study period duration. Moreover, the researchers noted that the study was conducted during the COVID-19 era, suggesting the possibility that COVID-19 vaccination or infection increased hand hygiene practices, which may have impacted psoriasis severity and NAPSI score accuracy.

Despite these limitations, the researchers believe the study demonstrated that a single injection of BoNT-A demonstrated prolonged efficacy in nail psoriasis compared with multiple sessions of TA injections.

“The difference between BoNT and TA injections during the follow-up period was significant,” wrote the researchers. “These findings contribute to our understanding of product half-life, highlighting that BoNT-A can provide long-lasting efficacy for up to 6 months whereas steroids last only 2 months.”

References

1. Juntongjin P, Srisinlapakig S, Nitayavardhana S. Botulinum toxin injection shows promise in nail psoriasis: a comparative randomized controlled trial. JAAD Int. Published online April 29, 2024. doi:10.1016/j.jdin.2024.03.021

2. Rosenberg J. Researchers outline treatment options for nail psoriasis, other common nail disorders. AJMC. September 9, 2022. Accessed May 14, 2024. https://www.ajmc.com/view/researchers-outline-treatment-options-for-nail-psoriasis-other-common-nail-disorders