A Chinese Herb, Indigo Naturalis, Extracted in Oil (Lindioil) Used Topically to Treat Psoriatic Nails: A Randomized Clinical Trial.

AChineseHerb, IndigoNaturalis, Extracted in Oil (Lindioil) Used Topically to Treat Psoriatic Nails: A Randomized Clinical Trial Indigo naturalis, a Chinese herb, has been used for decades.1 Olive oil was used to remove the blue component within indigo naturalis to yield a purple-red product to treat skin and nail psoriasis without obvious staining.2,3 This trial compared indigo naturalis extract in oil (Lindioil) with topical calcipotriol in treating psoriatic nails. Methods | Lindioil was prepared by mixing indigo naturalis powder with olive oil.4 Calcipotriol solution (Daivonex scalp solution, 50 μg/mL) was purchased from LEO Pharmaceutical Products, Ltd. Both were distributed in 5-mL eyedropper bottles. This trial was approved by the Chang Gung Medical Foundation Institutional Review Board and was randomized by participant, rater blinded, and active controlled. All participants provided written consent prior to the study. Participants, who were recruited from January 2011 through May 2012, were aged 20 to 65 years and had symmetrically comparable nail disease severity on each hand. The full study protocol synopsis can be found in Supplement 1. Participants applied 1 to 2 drops (0.05 mL/drop) of Lindioil to the fingernails of onehandandcalcipotriol to theother hand twice daily for 24 weeks. Participants were followed up every4weeks for 24weeksandphotographsof theirnailswere taken at each follow-up visit. Psoriatic nail severity was assessedby2blindeddermatologists (Y.-C.C. andY.-H.H.) using the single-hand Nail Psoriasis Severity Index (shNAPSI) and modified target NAPSI (mtNAPSI).4 Statistical analysiswasperformedwithSASstatistical software, version 9.3 (SAS Institute Inc). Themixed-effectmodel and pairwise comparisons were used, with P < .05 considered significant.