To the Editor:Hailey-Hailey disease (HHD),first discovered by the brothers Howard and Hugh Hailey,[1] is a genodermatosis at intertriginous sites.Mutation of ATP2C1 on chromosome 3q21-2 coding a calciumdependent ATPase gives rise to calcium dysfunction within keratinocytes,resulting in acantholysis due to a signal transduction disorder.[2] It has been suggested that this gene mutation combined with irritation such as frequent friction,cold,and ultraviolet exposure leads to the development of HHD.[3]