Pachyonychia Congenita

  • AD
  • Mutations in:
    • Keratin 6a or 16 (PC-6a/16; Type 1)
    • Keratin 6b or 17 (PC-6b/17; Type 2)
  • Painful focal PPK especially on soles (type 1>>type 2, especially K6a)
  • Hyperhidrosis, Acral blistering → difficulty ambulating
  • Debilitating
  • Secondary infections
  • Infancy: erythema of nail bed → development of hypertrophic nail dystrophy (pincer nails)
  • Follicular keratoses
  • Oral benign leukokeratosis (type 1>type 2)
    • Can rarely cause feeding difficulty
    • Can rarely involve larynx; stridor, hoarseness, obstruction
  • Steatocystoma multiplex, vellus hair cysts (K17), other cysts (type 2>type 1)
  • Natal/prenatal teeth (K17)
  • Treatment
    • Oral rosuvastatin (inhibits K6a expression)
    • Topical sirolimus (inhibis K6a, K16 expression)
    • Botulinum toxin injections
    • Matrixectomy usually not curative (keratins expressed in nail bed)
    • Keratolytics, topical/oral retinoids, prevention of superinfection, good oral hygiene, specialized tools for nails
    • Avoid friction, humidity
    • Injeção plantar de siRNA inhibits abnormal K6a and reduces calluses in congenital pachyonychia