Microneedle technology on par with topical steroids in nail psoriasis treatment

A novel transdermal device for the delivery of triamcinolone demonstrates efficacy comparable to that of conventional topical steroids in the treatment of nail psoriasis, according to a Singapore study.

“While new biologic therapies effective for both plaque psoriasis and psoriatic arthritis are promising for the treatment of nail psoriasis, topical treatments should still be the first-line therapy especially in individuals who have nail psoriasis with limited systemic involvement,” the researchers said.

A 4-month prospective randomized controlled trial was conducted in Singapore involving 25 individuals aged 22‒73 years, most of whom were Chinese (72 percent). Participants were randomly assigned to receive microneedle device-delivered topical steroids or control treatment (topical Daivobet gel).

Two independent dermatologists blinded to the treatment assignment scored the Nail Psoriasis Severity Index (NAPSI) during their visits at baseline and at 2 and 4 months. Treatment in both arms was discontinued after 2 months. The researchers then analysed average NAPSI on each hand.

Treatment randomization was equal to the left and right nail. Improvement in average NAPSI score occurred at 2 months in the control arm, but the treatment arm exhibited a greater, more sustained improvement of the NAPSI score at 4 months. [Ann Acad Med Singap 2022;51:16-23]

Both treatment and control groups had improvements in the average NAPSI score at 4 months relative to baseline, but only the NAPSI value improvement in controls at 2 months compared to baseline was statistically significant (p=0.0039). Notably, severe adverse events did not occur.

“While the observed higher NAPSI score at visit 2 for treatment arm was not statistically significant, the significantly better improvement scores at visit 2 for control group compared to treatment group could be attributed to a possible delay in any treatment effects from the microneedle compared to the control treatment,” the researchers explained.

“Nevertheless, any visible treatment effects seem to be similar between the two treatment arms after 4 months, suggesting that the microneedle treatment might have a slower onset or the effects could possibly be more persistent,” they added.

Microneedles are deemed superior to conventional transdermal delivery because it is minimally invasive, painless, convenient and promotes better patient compliance. [RSC Advances 2020;10:14040-14049]

Prior studies have tested microneedles in the administration of methotrexate, cyclosporin, and biologics, such as antitumour necrosis factor-alpha antibody. Results were satisfactory, with minimal side effects. [Pharm Res 2018;35:68; ACS Appl Mater Interfaces 2019;11:43588-43598; Drug Deliv 2009;16:52-56; Acta Biomater 2015;24:96-105; J Pharm Sci 2016;105:3453-3457]

Moreover, a pilot open trial that previously examined the use of a hyaluronic acid-based microneedle patch to treat psoriatic plaques reported promising results. However, evidence on microneedle patches to treat psoriatic nails was lacking. [Br J Dermatol 2018;178:e24-25]

“Further research with larger sample sizes is required to further support the use of microneedles to fill treatment gaps in terms of optimal dose adjustments and application frequency, as part of clinical management of nail psoriasis and for further development in this drug delivery field,” the researchers said.