title: Immunoglobulin G4-related diseases in the head and neck: a systematic review.
abstract: BACKGROUND
  Immunoglobulin G4 related disease (IgG4-RD) is a poorly understood chronic inflammatory disorder affecting the middle-aged and elderly that can present to the otolaryngologist. We aim to summarize the current literature regarding the manifestations and management of IgG4-RD in the head and neck.
  
  
  METHODS
  Pubmed and EMBASE were searched using the term relevant search algorithm utilizing keywords such as: IgG4 related disease, head and neck, orbit, salivary glands, sialadenitis, Kuttner, angiocentric eosinophilic fibrosis, submandibular, lacrimal, thyroid, dacryoadenitis, nasal, sinus, and Mikulicz's. Reference lists were searched for identification of relevant studies. Case reports, original research and review articles published in English from 1964 to 2014 whose major topic was IgG4-RD affecting the head and neck were included. Data regarding patient demographics, presentation, histopathology, management and treatment outcomes of IgG4-RD were extracted. Level of evidence was also assessed and data were pooled where possible. Three independent reviewers screened eligible studies; extracted relevant data and discrepancies were resolved by consensus, where applicable. Descriptive and comparative statistics were performed.
  
  
  RESULTS
  Fourty-three articles met our inclusion criteria. IgG4-RD most often presents as a mass lesion in the head and neck region. Common diagnostic features include: (1) elevated serum IgG4 level, (2) marked infiltration of exocrine glands by IgG4-positive plasma cells with fibrosis, and (3) marked improvement with corticosteroid therapy and additional immunosuppressive therapy in corticosteroid refractory cases. Early diagnosis and involvement of rheumatology is important in management.
  
  
  CONCLUSIONS
  IgG4-RD is a challenging non-surgical disease that has multiple manifestations in the head and neck. It must be distinguished from various mimics including malignancy, systemic diseases, and infectious. Otolaryngology-Head and Neck surgeons should be aware of this condition and its management.
authors.affiliation: Division of Otolaryngology-Head and Neck Surgery, 1E4 Walter MacKenzie Centre, University of Alberta, 8440 112 Street, Edmonton, AB, T6G 2B7, Canada. graemem@ualberta.ca.
authors.forename: Graeme B
authors.initials: GB
authors.lastname: Mulholland
authors.affiliation: Division of Otolaryngology-Head and Neck Surgery, 1E4 Walter MacKenzie Centre, University of Alberta, 8440 112 Street, Edmonton, AB, T6G 2B7, Canada. cxu@ualberta.ca.
authors.forename: Caroline C
authors.initials: CC
authors.lastname: Jeffery
authors.affiliation: Division of Otolaryngology-Head and Neck Surgery, 1E4 Walter MacKenzie Centre, University of Alberta, 8440 112 Street, Edmonton, AB, T6G 2B7, Canada. satija@ualberta.ca.
authors.forename: Paras
authors.initials: P
authors.lastname: Satija
authors.affiliation: Division of Otolaryngology-Head and Neck Surgery, 1E4 Walter MacKenzie Centre, University of Alberta, 8440 112 Street, Edmonton, AB, T6G 2B7, Canada. drdavidcote@me.com.
authors.forename: David W J
authors.initials: DW
authors.lastname: Côté
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D001327:Autoimmune Diseases / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology / Q000628:therapy; D002908:Chronic Disease; D003937:Diagnosis, Differential; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007249:Inflammation / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology; D010038:Otorhinolaryngologic Diseases / Q000175:diagnosis* / Q000188:drug therapy / Q000276:immunology*
chemical_list: D000305:Adrenal Cortex Hormones; D007074:Immunoglobulin G