True leukonychia in Crohn disease induced by selenium deficiency.

Report of aCase |Aman inhis 30spresentedwithan18-yearhistory of Crohndisease andhadundergonepartial resections of both small and large bowel 6 times. In recent years, the patient had been maintained on total parenteral nutrition, taking enteral nutritional products because of short-bowel syndrome.Hewas referred to our outpatient clinicwith a 2-week history of nail color changes. On physical examination, we found that the proximal halves of the affected nails of his fingers and toes were whitish; the distal halves were normal; and the 2 color zones were sharply demarcated (Figure, A). Routine laboratory examination for patients on total parenteral nutrition revealed a significantly low serum selenium level (2.0 μg/dL; reference level, 10.6-17.4 μg/dL). After treatment with 100 μg/d of selenium for 8 weeks to improve the selenium deficiency, interestingly, the proximal part of the nails at the nail base gradually turned normal, and the whitish part moved toward the distal direction without changing in appearance or size (Figure, B). Consequently, the whitish part regressed completely, and the nail conditions turned normal in 14 weeks (Figure, C).