title: "Cold air" and/or "talking" as cough triggers, a sign for the diagnosis of cough variant asthma.
abstract: BACKGROUND
  Fractional exhaled nitric oxide (FeNO) is considered an alternative marker of eosinophilic airway inflammation and is sometimes incorporated in the diagnosis of asthma. However, many patients with cough variant asthma (CVA) demonstrate an FeNO in the normal range. Therefore, additional information is needed to confirm the diagnosis of CVA, particularly in patients with low FeNO levels. We aimed to investigate the feasibility of using cough triggers to help diagnose CVA.
  
  
  METHODS
  We studied 163 patients presenting with prolonged/chronic cough alone (including 104 CVA patients) who underwent FeNO measurements and an airway responsiveness test, and answered a questionnaire listing 18 cough triggers. The sensitivity and specificity of FeNO levels and cough triggers for the diagnosis of CVA were determined.
  
  
  RESULTS
  CVA patients showed higher FeNO levels than non-CVA patients. When the cut-off value of FeNO levels for the diagnosis of CVA was set at 22ppb, its sensitivity was 57%. CVA patients more frequently responded to "cold air" and "talking" as cough triggers than non-CVA patients. When the analysis was confined to those with a low FeNO (<22ppb) group, the sensitivity and positive predictive values of "cold air" and "talking" for the diagnosis of CVA were 36% and 70% for "cold air", and 44% and 74% for "talking", respectively. Their specificity was 81%. "Cold air" was associated with airway hyperresponsiveness in all patients with an emphasis on those with low FeNO levels.
  
  
  CONCLUSIONS
  "Cold air" and/or "talking" as cough triggers could be signs for the diagnosis of CVA, particularly when FeNO levels are low.
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoinkawahra-cho, Sakyo-ku, Kyoto, Japan; Department of Respiratory Medicine, Allergy and Clinical Immunology, Graduate School of Medical Science, Nagoya City University, Aichi, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kanemitsu
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoinkawahra-cho, Sakyo-ku, Kyoto, Japan. Electronic address: hmatsumo@kuhp.kyoto-u.ac.jp.
authors.forename: Hisako
authors.initials: H
authors.lastname: Matsumoto
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoinkawahra-cho, Sakyo-ku, Kyoto, Japan.
authors.forename: Nuriamina
authors.initials: N
authors.lastname: Osman
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoinkawahra-cho, Sakyo-ku, Kyoto, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Oguma
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoinkawahra-cho, Sakyo-ku, Kyoto, Japan.
authors.forename: Tadao
authors.initials: T
authors.lastname: Nagasaki
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoinkawahra-cho, Sakyo-ku, Kyoto, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Izuhara
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoinkawahra-cho, Sakyo-ku, Kyoto, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Ito
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoinkawahra-cho, Sakyo-ku, Kyoto, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Tajiri
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoinkawahra-cho, Sakyo-ku, Kyoto, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Iwata
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoinkawahra-cho, Sakyo-ku, Kyoto, Japan; Department of Respiratory Medicine, Allergy and Clinical Immunology, Graduate School of Medical Science, Nagoya City University, Aichi, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Niimi
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoinkawahra-cho, Sakyo-ku, Kyoto, Japan.
authors.forename: Michiaki
authors.initials: M
authors.lastname: Mishima
mesh_terms: D000328:Adult; D000368:Aged; D000388:Air; D001249:Asthma / Q000175:diagnosis*; D015415:Biomarkers / Q000032:analysis; D003080:Cold Temperature; D003371:Cough; D045853:Exhalation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000032:analysis; D011237:Predictive Value of Tests; D011795:Surveys and Questionnaires
chemical_list: D015415:Biomarkers; D009569:Nitric Oxide
keywords: Chronic cough; Cold air; Cough variant asthma; Fractional nitric oxide; Talking