title: Treatment of atrophoderma of Pasini and Pierini-associated hyperpigmentation with the Q-switched alexandrite laser: a clinical, histologic, and ultrastructural appraisal.
abstract: OBJECTIVE
  Atrophoderma of Pasini and Pierini (APP) is an uncommon cutaneous disorder, with no known effective treatment, manifested by hyperpigmented patches that appear to be depressed compared with surrounding skin. This study investigated the effectiveness of the Q-switched alexandrite laser on a patient with extensive APP, and evaluated histopathologic and ultrastructural changes.
  
  
  METHODS
  A man with stable APP underwent Q-switched alexandrite laser treatment to a patch on the trunk. Biopsies were obtained from treated and untreated sites of involvement. Light and transmission electron microscopic evaluation was performed to investigate melanosome number, size, and volume, as well as melanin granule number and size.
  
  
  RESULTS
  After three treatment sessions, the treated area showed marked clinical improvement. Electron microscopy showed a 19% reduction in melanin granule number and size and a 65% reduction in melanosome number, size, and volume in larger melanosomes in treated compared with untreated sites.
  
  
  CONCLUSIONS
  Treatment of APP with the Q-switched alexandrite laser results in clinical improvement. Electron microscopic evaluation suggests that the mechanism may be a reduction in the number, size, and volume of larger melanosomes as well as a decrement in melanin granule number and size.
authors.affiliation: Department of Dermatology, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Arpey
authors.forename: D S
authors.initials: DS
authors.lastname: Patel
authors.forename: M S
authors.initials: MS
authors.lastname: Stone
authors.forename: J
authors.initials: J
authors.lastname: Qiang-Shao
authors.forename: K C
authors.initials: KC
authors.lastname: Moore
mesh_terms: D000328:Adult; D001284:Atrophy; D001608:Beryllium; D006801:Humans; D017495:Hyperpigmentation / Q000209:etiology / Q000473:pathology / Q000628:therapy*; D017075:Laser Coagulation / Q000379:methods*; D053685:Laser Therapy; D008297:Male; D020460:Melanosomes; D012867:Skin / Q000473:pathology* / Q000648:ultrastructure; D012871:Skin Diseases / Q000150:complications / Q000473:pathology / Q000628:therapy*; D013577:Syndrome; D016896:Treatment Outcome
chemical_list: C112654:alexandrite; D001608:Beryllium