Biotin or Pyridoxine Versus Combined Regimen in the Treatment of Onychoschizia

Background: Onychoschizia is characterized by distal nail plate splitting. Several therapeutic approaches exist, most of which are based on case reports or small non-comparative case series. Objective: To evaluate safety and efficacy of oral biotin and pyridoxine for treating onychoschizia. Patients and Methods: A retrospective comparative study was conducted among patients with idiopathic fingernail onychoschizia. Patients were prescribed 1 mg/day biotin, or 100 mg/day pyridoxine or both, for 3 months. Complete response (improvement of more than 90%) and partial response (improvement of more than 50%) were assessed after 6 to 9 months. Results: The study included 61 patients with fingernail onychoschizia (mean age 40.5 years [range 20-68 years]). The average number of affected fingernails was 7.0 (±2.0) per patient. The nail condition lasted 11.6 (±4.7) years on average. The combined treatment regimen achieved significantly higher rates of complete response compared to biotin or pyridoxine alone (69.6% vs 10%, 11.1%, respectively; P values < .001). Partial response (>50% improvement) was achieved in an additional 30.4%, 45%, and 38.9% of patients treated with combined regimen vs biotin or pyridoxine alone, respectively. No adverse events were recorded. Conclusions: This study demonstrates that the use of biotin and pyridoxine combination is an effective treatment for fingernail onychoschizia.