title: Frequency, treatment, and functional outcome in children with hypersensitivity pneumonitis.
abstract: BACKGROUND
  Hypersensitivity pneumonitis is a rare interstitial lung disease and very few data regarding frequency, treatment and outcome exist for children. Children identified with hypersensitivity pneumonia from a Danish national cohort with diffuse interstitial lung disease form the basis of this study focused on disease frequency, treatment, and functional outcome.
  
  
  METHODS
  Seventy-three children with clinical and radiological signs of interstitial lung disease verified by lung biopsy were identified over a 12-year period. Histologic material from all cases was reviewed by pathologists from the ChILD Clinical and Research Network, USA. Diagnosis of hypersensitivity pneumonitis was confirmed in 19 cases.
  
  
  RESULTS
  Incidence of hypersensitivity pneumonitis was approximately 2/year and with a point prevalence of 4/1,000,000 children. The median (range) number of monthly courses with intravenous methylprednisolone was 15 courses (8-34) in resolved cases, but in the vast majority (92%), mono-therapy with high dose pulse methylprednisolone treatment was not sufficient for acceptable improvement. Lung function, DLco and DLco/VA increased significantly after 3 and 6 months of treatment compared to baseline (P < 0.05). However, without reaching normal values [mean SDS (range) FEV(1) -0.66 (-1.88 to 0.41) and FVC -0.67(-1.94 to 0)]. No mortality was seen.
  
  
  CONCLUSIONS
  Incidence and point prevalence of hypersensitivity pneumonitis in Denmark was 2/year and 4/1.000.000 children. High dose intravenous methylprednisolone constituted the basic treatment, but in most cases supplemental anti-inflammatory therapy was necessary. Outcome was acceptable without any mortality. Nevertheless, both lung function and diffusion capacity were in subnormal level though without any clinically functional impact.
authors: Danish ChILD Center, Pediatric Pulmonary Service, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark. fbuchvald@dadlnet.dk
authors: Frederik
authors: F
authors: Buchvald
authors: Bodil Laub
authors: BL
authors: Petersen
authors: Karen
authors: K
authors: Damgaard
authors: Robin
authors: R
authors: Deterding
authors: Claire
authors: C
authors: Langston
authors: Leland L
authors: LL
authors: Fan
authors: Gail H
authors: GH
authors: Deutsch
authors: Megan K
authors: MK
authors: Dishop
authors: Lene Agergaard
authors: LA
authors: Kristensen
authors: Kim G
authors: KG
authors: Nielsen