Treatment of psoriatic nails with indigo naturalis oil extract: a non-controlled pilot study.

BACKGROUND: In the treatment of nail psoriasis, standardized therapeutic regimens are currently lacking. OBJECTIVE: To evaluate the therapeutic efficacy of indigo naturalis oil extract in patients with nail psoriasis. METHODS: Patients with nail psoriasis applied indigo naturalis oil extract on affected nails twice daily for 24 weeks. Efficacy was evaluated using the Nail Psoriasis Severity Index (NAPSI) and modified target NAPSI for the single most severely affected nail. RESULTS: Twenty-eight out of 32 patients completed the study. The mean NAPSI was 36.1 ± 14.7 at baseline and decreased to 14.9 ± 11.1 at week 24 while the mean modified target NAPSI was 11.7 ± 3.9 at baseline and decreased to 3.6 ± 3.2 at week 24. CONCLUSIONS: Indigo naturalis oil extract appeared to improve nail psoriasis. Although preliminary, these results indicate that it could provide a novel therapeutic option for nail psoriasis, a disease notoriously difficult to treat.