Dermatopathology in Historical Perspective: PDF OnlyBondeson Jan M.D.The American Journal of Dermatopathology: December 1993 - p 594-599 Buy Abstract Pachyonychia congenita is an uncommon type of ectodermal dysplasia, characterized by thickened, dystrophic nails and hyperkeratotic skin lesions. In the literature, it has been widely accepted that the first cases of this syndrome were published in the first years of the 20th century. However, a search of the older literature reveals several older cases of definite pachyonychia congenita, some of them from the 17th and 18th centuries. In 1716, the Danish physician Musaeus described a case of the pachyonychia congenita syndrome in some detail, with an excellent plate showing all the major symptoms. © Lippincott-Raven Publishers.