Pachyonychia congenita is a rare genetic disorder classified in clinic
al subtypes. Late onset of the disease has recently been described and
designated as pachyonychia congenita tarda. A patient in whom typical
manifestations of pachyonychia congenita appeared at the age of 39 ye
ars is described. This report substantiates previous observations on t
he phenomenon of late-onset pachyonychia congenita.