title: The use of specific inhalation challenge in hypersensitivity pneumonitis.
abstract: OBJECTIVE
  The diagnosis of hypersensitivity pneumonitis remains a dilemma because of the absence of any characteristic features able to distinguish it from other interstitial lung diseases. We analyze the current role of the specific inhalation challenge (SIC) in the diagnosis of this entity.
  
  
  RESULTS
  Few descriptions of the use of SIC for the diagnosis of hypersensitivity pneumonitis have been published in recent years. In fact, hypersensitivity pneumonitis is still diagnosed on the basis of clinical criteria, as there is no agreement on the diagnostic utility of SIC. Two major reviews carried out in the past year have concluded that this test is not standardized and is usually unnecessary; however, a third study found that the test can indeed recreate the symptoms and functional abnormalities in the laboratory, and may therefore be of considerable use in the diagnosis of hypersensitivity pneumonitis.
  
  
  CONCLUSIONS
  Hypersensitivity pneumonitis remains a diagnostic challenge. Given that the main cause of the disease is sensitization and hyper-responsiveness to specific antigens in susceptible individuals, SIC is an obvious candidate as the gold standard for diagnosis of this entity. The present review analyzes the reasons for the test's limited use, assesses its diagnostic utility, and proposes a basis for its standardization.
authors: Servei de Pneumologia, Hospital Vall d'Hebron, Universidad Autònoma de Barcelona, Barcelona, Spain. xmunoz@vhebron.net
authors: Xavier
authors: X
authors: Munoz
authors: Ferran
authors: F
authors: Morell
authors: Maria-Jesus
authors: MJ
authors: Cruz
mesh_terms: D000280:Administration, Inhalation; D000485:Allergens / Q000008:administration & dosage* / Q000276:immunology; D000542:Alveolitis, Extrinsic Allergic / Q000175:diagnosis* / Q000276:immunology; D000818:Animals; D003937:Diagnosis, Differential; D006801:Humans; D007114:Immunization / Q000379:methods* / Q000592:standards; D007159:Immunologic Tests / Q000379:methods* / Q000592:standards
chemical_list: D000485:Allergens