title: Treatment of lichen pilaris with a Q-switched Nd:YAG laser in quasi long-pulsed mode: A case report (a secondary publication).
abstract: OBJECTIVE
  Lichen pilaris is a very common disease typically seen among young adults on their upper arms as a manifestation of hyperkeratotic lesions occurring in the pores. Only a few treatments have been reported as significantly effective, so often natural resolution over time is the only option. The present study examined the use of a 1064 nm Q-switched Nd:YAG laser (QSNY) in quasi long-pulsed mode, in an attempt to treat a case of lichen pilaris.
  
  
  METHODS
  A 33-year-old male presented with light-brown aggregated papules observed on both sides of the upper arms. The affected areas were treated every other week (QSNY, pulse width 300 µs, pulse energy 3.0 J/cm(2), spot size 6 mm and repetition rate 10 Hz). Clinical photography was taken of the lesions at baseline and three months after the final treatment in addition to macrophotography and 3-D photography, biopsies being taken at both time points for histological comparison.
  
  
  RESULTS
  The clinical photography and objective image evaluation demonstrated shrinkage of pores and improvement of the unevenness of the skin. Histological examination suggested that the effect of the micropulsed QSNY on the horny layer, epidermal keratinocytes and dermal collagen resulted in a peeling effect and increased dermal collagen density, which eventually led to the shrinkage of the pores and improvement of the skin condition.
  
  
  CONCLUSIONS
  The results of this single patient case report suggest that the micropulsed QSNY could be an effective treatment option for lichen pilaris, improvement of which is often difficult. Further studies with an appropriately-sized population are merited to confirm these preliminary results.
authors.affiliation: Division of Dermatology, Miyazaki Hospital, Nagasaki, JAPAN.
authors.forename: Atsuto
authors.initials: A
authors.lastname: Ueda
keywords: Histological examination; Lichen pilaris; Q-switched Nd:YAG Laser; Quasi long-pulsed mode