Median canaliform nail dystrophy in a 2-year-old boy: Case report and review of the literature.

Median canaliform nail dystrophy (MCD) is a rare nail abnormality with an unknown etiology. We report the case of MCD of both great toenails in a 2-year-old boy presenting with a fir tree nail pattern and longitudinal splits. MCD was treated with topical marigold therapy (Tagetes sp.). By 15 weeks, the proximal 50% of the MCD had normalized. The report highlights a potential new treatment of marigold therapy for MCD.