Mastocytosis-induced nyctalopia

Systemic mastocytosis is characterized by an increased number of mast cells in multiple organs particularly skin. A 55-year-old man with mastocytosis presented with nyctalopia caused by malabsorption of vitamin A, Diagnosis was made by documenting a low vitamin A level and an ERG that showed rod-cone deficiency with rods affected more than cones. Vitamin A therapy led to return of good visual function. To our knowledge, this is the first reported case of mastocytosis induced nyctalopia. Vitamin A deficiency should be considered as a potential cause of visual loss in patients with sudden onset of night blindness.