Pachyonychia congenita with steatocystoma multiplex. A report of two cases and a discussion of the classification.

Pachyonychia congenita is a rare syndrome in which the main and most common clinical sign is onychodystrophy of all finger and toe nails. The most frequent type of transmission seems to be autosomal dominant, but recessive forms have also been described. Typical onychodystrophy can be associated with other clinical manifestations. The most recent literature refers to descriptions of about 250 cases up until 1993. Numerous classifications of pachyonychia congenita have been suggested by several authors over the years. We report two cases of pachyonychia congenita in association with steatocystoma multiplex in a mother and son.