Median canaliform nail dystrophy of Heller in a patient with atopic dermatitis: a "miraculous" healing with Dupilumab.

Median canaliform dystrophy of Heller is a relatively rare nail abnormality characterized by central single longitudinal split with an inverted fir tree pattern, that commonly involves the thumb nails, rarely other finger nails. The pathogenesis is not entirely clear, the most common hypothesis is repetitive trauma to the proximal nail fold and the underlying nail matrix, also self-induced, or compression by subungual tumors. Familiar cases have been reported. But commonly the cause is idiopathic.