title: An appraisal of oral retinoids in the treatment of pachyonychia congenita.
abstract: BACKGROUND
  Pachyonychia congenita (PC), a rare autosomal-dominant keratin disorder caused by mutations in keratin genes KRT6A/B, KRT16, or KRT17, is characterized by painful plantar keratoderma and hypertrophic nail dystrophy. Available studies assessing oral retinoid treatment for PC are limited to a few case reports.
  
  
  OBJECTIVE
  We sought to assess overall effectiveness, adverse effects, and patient perspective in patients with PC receiving oral retinoids.
  
  
  METHODS
  In a questionnaire-based retrospective cross-sectional survey of 30 patient with PC assessing oral retinoids (10-50 mg/d for 1-240 months), we determined the clinical score, satisfaction score, visual analog pain scale, and adverse effects.
  
  
  RESULTS
  In 50% of patients there was thinning of hyperkeratoses (average improvement 1.6 on a scale from -3 to +3) (95% confidence interval 1.2-1.9, P < .001). In all, 14% observed amelioration of their pachyonychia; 79% did not experience any nail change. The self-reported overall satisfaction score with oral retinoid treatment was 2 or greater in 50% of the patients (mean 4.5 on a scale of 1-10). Although 33% reported decreased and 27% increased plantar pain with treatment, 40% did not notice any pain change. All patients experienced adverse effects, and 83% reported to have discontinued medication. Risk/benefit analysis favored lower retinoid doses (≤25 mg/d) over a longer time period (>5 months), compared with higher doses (>25 mg/d) for a shorter time (≤5 months).
  
  
  CONCLUSIONS
  The retrospective, cross-sectional study design is prone to a recall bias.
  
  
  CONCLUSIONS
  Oral retinoids are effective in some patients with PC. However, many patients discontinued medication because adverse effects outweighed the benefits. Careful dose titration is warranted in patients informed about potential adverse effects.
authors: Department of Dermatology, Innsbruck Medical University, Innsbruck, Austria.
authors: Robert
authors: R
authors: Gruber
authors: Michael
authors: M
authors: Edlinger
authors: Roger L
authors: RL
authors: Kaspar
authors: C David
authors: CD
authors: Hansen
authors: Sancy
authors: S
authors: Leachman
authors: Leonard M
authors: LM
authors: Milstone
authors: Frances J D
authors: FJ
authors: Smith
authors: Alexis
authors: A
authors: Sidoroff
authors: Peter O
authors: PO
authors: Fritsch
authors: Matthias
authors: M
authors: Schmuth