Botulinum toxin A might provide efficacious treatment option for nail psoriasis

Botulinum toxin A may be an effective treatment option for nail psoriasis, a hard-to-treat condition for which new treatment options are highly needed. In a randomised controlled trial, a single injection of botulinum toxin A appeared to be equally efficacious as multiple injections of corticosteroids.

“The current treatment options for patients with nail psoriasis come with substantial limitations,” stated Dr Premjit Juntongjin (Thammasat University, Thailand) [1]. “For example, topical treatments are often poorly absorbed, whereas systemic treatments can induce systemic adverse events. Also, biologics are costly and local injections are often painful and require multiple sessions.” For this purpose, Dr Juntongjin and co-investigators designed a study to investigate an alternative treatment for nail psoriasis.

The study randomised 64 nails of 16 individuals with nail psoriasis to 1 of 4 investigational conditions:

• a single intralesional botulinum toxin A injection,
• 2 intralesional injections with triamcinolone acetonide,
• topical calcipotriol/betamethasone, once daily,
• wait-and-see.

After a treatment period of 16 weeks and a follow-up period of 8 weeks, the investigators analysed the efficacy of the treatment options.

All active treatment options significantly outperformed the wait-and-see approach in terms of the percentage change in the total target Nail Psoriasis Severity Index (NAPSI) score (P<0.01). “Interestingly, multiple corticosteroid injections were not superior to a single botulinum toxin A injection at any time point,” commented Dr Juntongjin. Looking at the nail bed NAPSI score, botulinum toxin A was associated with significantly improved outcomes compared with corticosteroid injections at week 24 (P=0.002). There were no significant differences in pain or adverse reactions when the different treatment regimens were compared.

“The results of the current study demonstrate that botulinum toxin A may be an efficacious treatment option for patients with nail psoriasis, a refractory and difficult-to-treat condition,” decided Dr Juntongjin. “The effect of botulinum toxin A on neurogenic inflammation, a less explored pathogenesis of psoriasis, may explain the effect that we observed in this trial.”

1. Juntongjin P, et al. Efficacy of intralesional botulinum toxin, intralesional corticosteroids and topical vitamin D/steroid in nail psoriasis: a comparative randomized intra-individual controlled study. Late-breaker Session 1, WCD 2023, 3–8 July, Singapore, Singapore.