Pachyonychia congenita with late onset (PC tarda)

Abstract

Pachyonychia congenita is a rare type of ectodermal dysplasia further classified into 4 types. Cutaneous manifestations seen in most of the cases of Pachyonychia congenita include palmoplantar keratoderma, follicular hyperkeratosis, wedge shaped nails, oral leukokeratosis and woolly hair. A 25-year-old male presented to us with thickened nails and scanty scalp hair. On examination, we noticed hyperkeratotic plaques over both the soles, palmoplantar hyperhidrosis and yellowish discoloration, wedging with subungual hyperkeratosis of all the nails. Follicular hyperkeratotic papules and steatocystoma multiplex were also observed over the scalp and face. The patient had history of natal teeth and on dental examination, lower central incisors were absent. All cutaneous changes in our case had manifested first in the 2nd decade except for natal teeth. All the above features suggested the diagnosis of pachyonychia congenita with late onset (PC tarda), which is an infrequently reported rare variant.

A systematic review of reported cases of pachyonychia congenita tarda

“…The presence of alopecia in one case is suggestive of an alternative diagnosis such as steatocystoma multiplex (which has been reported with alopecia) or Clouston syndrome . An additional three cases describe endocrinological abnormalities, which would make an alternative endogenous cause for the late‐onset nail changes much more likely than PCT. One case described PPK without nail changes, more suggestive of PPK than PC, and the presence of multiple dermal cysts with a positive family history raises the possibility of steatocystoma multiplex in another case (Table ).…”

“…The remaining 19 articles were retrieved for full text screening; following this, 6 further articles were excluded as not containing individual demographic or clinical data on manifestations of disease. This left a total of 13 articles containing 19 individual cases of PCT, which were included in this review. From these 19 cases, a total of 3 unique genetic polymorphisms were identified.…”

Pachyonychia congenita: Brief appraisal of history and current classification

“…in the July-August 2016 issue of the Journal. [ 1 ] However, we would like to emphasize certain points regarding the history and current classification system of this rare disorder of keratinization [a Mendelian disorder of cornification ( MeDOC )].…”

“… It is almost universally believed that the disorder was first described by Müller in 1904. [ 1 ] However, the first case of PC (with cutaneous horns) was originally described by St George Ash in an Irish girl as early as 1685 (quoted in[ 2 ])[ 3 ] A large amount of clinicogenetic information, based on the data collected from the International Pachyonychia Congenita Research Registry (IPCRR), has become available in the last several years. This has formed the basis of a new classification system for PC, gradually replacing earlier classifications, and is based almost exclusively on the mutated genes.…”

“…It is almost universally believed that the disorder was first described by Müller in 1904. [ 1 ] However, the first case of PC (with cutaneous horns) was originally described by St George Ash in an Irish girl as early as 1685 (quoted in[ 2 ])[ 3 ]…”