title: Pruritic papular eruption and eosinophilic folliculitis associated with human immunodeficiency virus (HIV) infection: a histopathological and immunohistochemical comparative study.
abstract: BACKGROUND
  Among the papular-pruriginous dermatoses related to human immunodeficiency (HIV) infection, two entities remain poorly differentiated leading to confusion in their diagnosis: HIV-related pruritic papular eruption (HIV-PPE or prurigo) and eosinophilic folliculitis (HIV-EF).
  
  
  OBJECTIVE
  To establish histopathological and immunohistochemical parameters to differentiate between two conditions associated with HIV infection, the pruritic papular eruption (HIV-PPE) and eosinophilic folliculitis (HIV-EF).
  
  
  METHODS
  Clinically typical HIV-PPE (18 cases) and HIV-EF (10 cases) cases were compared with each other in terms of the following topics: clinical and laboratory features (gender, age, CD4+ cell and eosinophil count), histopathological features (hematoxylin-eosin and toluidine blue staining) and immunohistochemical features (anti-CD1a, anti-CD4, anti-CD7, anti-CD8, anti-CD15, anti-CD20, anti-CD30, anti-CD68/macrophage and anti-S-100 reactions).
  
  
  RESULTS
  Among the HIV-EF patients, we found an intense perivascular and diffuse inflammatory infiltration compared with those patients with HIV-PPE. The tissue mast cell count by toluidine staining was higher in the HIV-EF patients, who also presented higher expression levels of CD15 (for eosinophils), CD4 (T helper), and CD7 (pan-T lymphocytes) than the HIV-PPE patients.
  
  
  CONCLUSIONS
  Only quantitative differences and not qualitative differences were found.
  
  
  CONCLUSIONS
  These data indicate that HIV-related PPE and EF could possibly be differentiated by histopathological and immunohistochemical findings in addition to clinical characteristics. In fact, these two inflammatory manifestations could be within the spectrum of the same disease because only quantitative, and not qualitative, differences were found.
authors.affiliation: Department of Dermatology, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: João Paulo Junqueira Magalhães
authors.initials: JP
authors.lastname: Afonso
authors.forename: Jane
authors.initials: J
authors.lastname: Tomimori
authors.forename: Nilceo Schwery
authors.initials: NS
authors.lastname: Michalany
authors.forename: Suely
authors.initials: S
authors.lastname: Nonogaki
authors.forename: Adriana Maria
authors.initials: AM
authors.lastname: Porro
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D003937:Diagnosis, Differential; D004802:Eosinophilia / Q000276:immunology / Q000473:pathology* / Q000821:virology; D005260:Female; D005499:Folliculitis / Q000276:immunology / Q000473:pathology* / Q000821:virology; D015658:HIV Infections / Q000150:complications* / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011537:Pruritus / Q000276:immunology / Q000473:pathology* / Q000821:virology; D012189:Retrospective Studies; D012867:Skin / Q000473:pathology; D017444:Skin Diseases, Papulosquamous / Q000276:immunology / Q000473:pathology* / Q000821:virology; D012872:Skin Diseases, Vesiculobullous / Q000276:immunology / Q000473:pathology* / Q000821:virology
chemical_list: D015415:Biomarkers