Autosomal recessive pachyonychia congenita.

We report the second and third cases of pachyonychia congenita inherited as an autosomal recessive disorder. Our cases were unusual, with the fingernails showing a striking leukonychia and appearing clinically as Terry's nails. These patients were originally diagnosed as having epidermolysis bullosa simplex because of a history of a life-long blistering disorder. The clinical features and inheritance of pachyonychia congenita, as well as the reasons for the long delay in diagnosis of our cases, are discussed.