title: Biopsies of facial dermatoses made simple.
abstract: BACKGROUND
  Biopsy of the face is rarely done for inflammatory skin diseases, unless the entire process is confined to the face.
  
  
  OBJECTIVE
  We hypothesized that facial dermatitis has a differential diagnosis that is more limited than the differential diagnosis of inflammatory skin diseases that affect other parts of the body. To our knowledge, the classification of inflammatory skin diseases occurring on the face has never been conducted before in the English literature.
  
  
  METHODS
  The most-recent 100 facial biopsies of inflammatory skin conditions were retrieved from our files, and the cases were categorized into the main inflammatory skin patterns.
  
  
  RESULTS
  Forty-seven cases (47%) were categorized as interface dermatitis, 2 cases (2%) as psoriasiform dermatitis, 11 cases (11%) as spongiotic dermatitis, 16 cases (16%) as diffuse and nodular dermatitis, 8 cases (8%) as perivascular dermatitis, 14 cases (14%) as folliculitis and perifolliculitis, 1 case (1%) as panniculitis, and 1 case (1%) as fibrosing dermatitis. The number of diagnostic entities represented within each of these patterns was small.
  
  
  CONCLUSIONS
  We believe that facial dermatitis should have its own more-circumscribed differential diagnosis. From a practical viewpoint, many of the inflammatory skin diseases that affect other parts of the body should be excluded from the differential diagnosis after the tissue is determined to be from a facial skin biopsy, and others should not be considered unless the biopsy is from the face.
authors.affiliation: From the Department of Pathology, University of Toronto, Toronto, Ontario, Canada (Dr Al-Mohammedi); and.
authors.forename: Faisal
authors.initials: F
authors.lastname: Al-Mohammedi
authors.forename: Richard I
authors.initials: RI
authors.lastname: Crawford
authors.forename: Magdalena
authors.initials: M
authors.lastname: Martinka
mesh_terms: D001706:Biopsy; D012628:Dermatitis, Seborrheic / Q000175:diagnosis; D003937:Diagnosis, Differential; D004485:Eczema / Q000175:diagnosis; D005148:Facial Dermatoses / Q000145:classification / Q000175:diagnosis* / Q000473:pathology; D005153:Facial Neoplasms / Q000175:diagnosis; D005499:Folliculitis / Q000175:diagnosis; D005549:Foreign-Body Reaction / Q000175:diagnosis; D006099:Granuloma / Q000175:diagnosis; D006801:Humans; D018442:Lymphoma, B-Cell, Marginal Zone / Q000175:diagnosis; D015434:Panniculitis / Q000175:diagnosis; D010859:Pigmentation Disorders / Q000175:diagnosis; D011565:Psoriasis / Q000175:diagnosis; D012393:Rosacea / Q000175:diagnosis