title: Porokeratotic adnexal ostial naevus: review on the entity and therapeutic approach.
abstract: BACKGROUND
  Porokeratotic adnexal ostial nevus (PAON) is a term that encompass porokeratotic eccrine ostial and dermal duct naevus and porokeratotic eccrine and hair follicle naevus. PAON is a rare adnexal hamartoma characterized by the presence of a cornoid lamella exclusively overlying eccrine acrosyringia or over both, eccrine acrosyringia and hair follicles.
  
  
  OBJECTIVE
  Most of the articles on PAON report its clinical or histopathological characteristics but literature review offer scarce data on the evolution or treatment. We have reviewed it.
  
  
  METHODS
  We report an 8-year-old boy with presence of bilateral asymtomatic verrucous lesions mostly in left side of the body without other added abnormalities through the twelve-year follow-up. As our case presented cornoid lamella overlying eccrine acrosyringia and hair follicles we diagnosed PEHFN. He received treatment with CO2 ablation in 2004 and in 2012 with marked improvement.
  
  
  RESULTS
  Review of the previous reported cases of PAON show that it is mostly unilateral and that some patients have coexisting problems like seizures, left hemiparesis, scoliosis, deafness, developmental delay, palmoplantar keratoderma, psoriasis, hyperthyroidism, polinerupathy, breast hipoplasia and KID.
  
  
  CONCLUSIONS
  PAON responded with tazaroten gel, dithranol short-contact treatment and topical photodynamic therapy but laser treatments appear to be more efficient in most patients.
authors.affiliation: Department of Dermatology, Hospital Infanta Cristina, Parla, Madrid, Spain.|Kempf und Pfaltz Histologische Diagnostik, Zurich, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Llamas-Velasco
authors.affiliation: Dermatology Practice Dermapoint, Vaduz, Liechtenstein.
authors.forename: N
authors.initials: N
authors.lastname: Hilty
authors.affiliation: Kempf und Pfaltz Histologische Diagnostik, Zurich, Switzerland.
authors.forename: W
authors.initials: W
authors.lastname: Kempf
mesh_terms: D001365:Axilla; D002648:Child; D004439:Eccrine Glands; D006119:Groin; D018859:Hair Follicle; D006801:Humans; D054020:Lasers, Gas / Q000627:therapeutic use*; D008297:Male; D018330:Nevus, Intradermal / Q000473:pathology* / Q000601:surgery*; D017499:Porokeratosis / Q000473:pathology*; D013544:Sweat Gland Neoplasms / Q000473:pathology* / Q000601:surgery*