title: The relevance of recognizing clinical and morphologic features of pityriasis lichenoides: clinicopathological study of 29 cases.
abstract: BACKGROUND
  Pityriasis lichenoides (PL) is a lymphoproliferative disease of unknown origin; its diagnosis is based on clinical characteristics and confirmed by histology.
  
  
  OBJECTIVE
  To describe clinical and histological features of PL in 29 pediatric patients.
  
  
  METHODS
  Retrospective descriptive study of children (patients less than 15 years old) diagnosed with PL between 1986 and 2010 at a Reference Service in Pediatric Dermatology from South Brazil.
  
  
  RESULTS
  Twenty-nine PL cases were found by chart review in 24 years. Mean age of diagnosis was 8 years (22 to 178 months) and a mean time of diagnosis was 13.8 months (1 to 120 months). Twenty cases (69%) were male. Seasonal correlation was found with colder months in 62% of cases (p<0.01). Clinical diagnosis was pityriasis lichenoides chronica (PLC) in 25 cases, and pityriasis lichenoides et varioliformis acuta (PLEVA) in four. Itching was the main reported symptom occurring in 13 (45%). Fourteen cases had been histologically evaluated. In six, microscopic findings were consistent with PLC, in four consistent with PLEVA, and four biopsies exhibited mixed characteristics of both forms. Concordance between clinical and histological diagnosis was seen in most cases.
  
  
  CONCLUSIONS
  PL occurs in children and young adults, more commonly in males, and during cold months. PLC was the more frequent clinicohistologic form, and necrotic lesions characterized PLEVA. Associating clinical and histological findings is important for differentiating between PLC and PLEVA diagnosis.
authors.affiliation: Division of Pediatrics, ITPAC-Porto Nacional, Tocantins, Brazil.
authors.forename: Jandrei Rogério
authors.initials: JR
authors.lastname: Markus
authors.forename: Vânia Oliveira
authors.initials: VO
authors.lastname: Carvalho
authors.forename: Monica Nunes
authors.initials: MN
authors.lastname: Lima
authors.forename: Kerstin Taniguchi
authors.initials: KT
authors.lastname: Abagge
authors.forename: Alexandre
authors.initials: A
authors.lastname: Nascimento
authors.forename: Betina
authors.initials: B
authors.lastname: Werner
keywords: child; pityriasis lichenoides; pityriasis lichenoides chronica; pityriasis lichenoides et varioliformis acuta