title: Prediction of obeche wood-induced asthma by specific skin prick testing.
abstract: BACKGROUND
  It has previously been shown that a positive skin prick test (SPT) result is a good predictor of a positive specific inhalation challenge (SIC) in patients with occupational asthma (OA) related to wheat or rye flours. This association has not been previously studied in OA attributable to obeche wood.
  
  
  OBJECTIVE
  To describe a clinical series of patients with OA induced by obeche wood. To investigate if the SPT result can be used as a predictor for the outcome of SIC tests.
  
  
  METHODS
  OA was diagnosed according to patient history, lung function examinations and SIC tests, as well as the determination of obeche SPTs. We analysed sensitivity, specificity and positive (PPV) and negative predictive values (NPV) at different wheal sizes of the SPTs and drew receiver-operating characteristic plots using the SIC test result as the gold standard.
  
  
  RESULTS
  Obeche wood SIC tests were performed on 34 symptomatic workers. Of these, 27 workers had a positive test result and were diagnosed as having OA. The minimal cut-off value with a PPV of 100% was an SPT wheal of 3.5 mm from obeche wood. This means that all workers with a wheal size of ≥ 3.5 mm from obeche wood had a positive SIC.
  
  
  CONCLUSIONS
  Positive SPT results in symptomatic workers were good predictors of a positive SIC. SIC with obeche wood may be unnecessary in strongly sensitized workers.
authors.affiliation: Finnish Institute of Occupational Health, Helsinki, Finland. timo.hannu@helsinki.fi
authors.forename: T
authors.initials: T
authors.lastname: Hannu
authors.forename: I
authors.initials: I
authors.lastname: Lindström
authors.forename: P
authors.initials: P
authors.lastname: Palmroos
authors.forename: O
authors.initials: O
authors.lastname: Kuuliala
authors.forename: R
authors.initials: R
authors.lastname: Sauni
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D059366:Asthma, Occupational / Q000175:diagnosis*; D001985:Bronchial Provocation Tests / Q000379:methods; D004391:Dust; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D012680:Sensitivity and Specificity; D012882:Skin Tests / Q000379:methods; D014934:Wood / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D004391:Dust
keywords: Inhalation challenge test; occupational asthma; skin prick test; wood dust.