Efficacy and safety of intramatricial triamcinolone acetonide injections in nail lichen planus: A retrospective data analysis.

Background: Nail lichen planus (NLP) impacts 10-15% of patients with lichen planus and is characterized by discomfort and the potential for permanent damage. Intralesional triamcinolone acetonide (TA) is a first-line treatment; however, comprehensive efficacy data is lacking.

Objective: To evaluate and compare changes in nail lichen planus severity using the Nail Lichen Planus Severity Index (NALSI) in affected fingernails and toenails treated with intramatricial TA (5 mg/ml) injections at 4-weekly and 8-weekly intervals, respectively.

Methods: A retrospective analysis was done for 17 NLP patients treated over 11 years with intramatricial TA (5 mg/ml). Photographic records from each visit were analysed to score disease severity using NALSI. Comparison was made of the percentage of fingernails versus toenails achieving NALSI-50 (50% reduction in NALSI over baseline) at the 3rd and 6th injections.

Results: These 17 patients had 232 nails (68.2%) affected by lichen planus, of which 130 (56%) were fingernails and 102 (44%) were toenails. The mean baseline NALSI of 7.4 ± 2.7 for fingernails, decreased to 6.6 ± 2.7 at the 3rd session, and 4.2 ± 3.2 at 6th session, while for toenails it dropped from 7.02 ± 2.6 to 6.6 ± 2.5 and 5.9 ± 3.0, respectively. By the treatment endpoint (4/8 weeks after fifth injection, respectively, for fingernails and toenails), NALSI-50 reduction was achieved in 40.7% fingernails and 10.8% toenails; while NALSI-75 reduction was achieved in 21.5% fingernails and 4.9% toenails, respectively. Throughout the course of the therapeutic intervention, the proportion of fingernails exhibiting irreversible alterations remained stable at 11.5%. However, a notable increase was observed for toenails, rising from 11.7% at baseline to 13.7% by the conclusion of the study. The adverse effects included pain (23.5% of patients), proximal nail-fold hyperpigmentation and atrophy (23.5%), and subungual hematoma (17.6%).

Conclusions: Intramatricial TA (5 mg/ml) injections are safe and effective in the treatment of NLP, with greater efficacy being noted in fingernails.