Pachyonychia congenita affecting only the nails: A case report

ABSTRACT

INTRODUCTION@#The nails have many functions for daily life including protection of the digits against different kinds of trauma. The nail apparatus is composed of multiple kinds of keratins. Defects in keratin may produce several genodermatoses, which include Pachyonychia congenita. This is a rare genodermatosis that is either automosal dominant or sporadic. The usual involved keratins are KRT6a, KRT6b, KRT6C, Kl 6 and Kl 7. Keratin defects may manifest on the hair, mucosa, skin and nails. Different presentations of each patient depends on the involved mutated keratins, In rare cases, nail dystrophy may be the only manifestation of the keratin defect.@*CASE SUMMARY@#A 23 -year-old female presented with a 13-year-history of nail thickening on both fingernails and toenails with no other associated symptoms. She denied oral and skin lesions. She had been unsuccessfully treated with both oral and topical antifungals by several dermatologists. No family members have any similar conditions. She admitted to having hoarseness. On physical examination, nails of both hands and feet marked subungual hyperkeratosis, yellowish to brown- gray discoloration and hypercurvature and rough surface of all 20 nails. The histopathology report revealed marked compact hyperkeratosis, hypergranulosis, papillomatosis and acanthosis. Fungal culture and PAS stain revealed no fungal elements. Patient responded well to nail avulsion and good nail regrowth was noted. She plans treatment of all nails with avulsion.@*CONCLUSION@#Thorough history, physical examination and histology may help confirm the diagnosis of Pachyonychia congenita, which at times may be mistaken for other nail problems. Treatment is based upon the clinical presentation of the patient. Prognosis for life is good but complications such as infections should be properly addressed.