title: Avoiding misdiagnosis in patients with dyspnea and wheezing: a case report illustrating the clinical implications of fixation error.
abstract: Bronchial asthma is a heterogeneous respiratory condition which can be mimicked by a wide range of pathologies including upper airways stenosis. The accurate diagnosis of asthma, as with other conditions, may be influenced by fixation errors, which are common in medicine and occur when a physician concentrates on only one element of a clinical case without considering other relevant aspects. Here we report a challenging case characterized by the contemporaneous presence of a common disease, asthma, together with a rare respiratory disease, idiopathic tracheal stenosis.
  
  
  
  The 56-year-old female patient, a former smoker, was referred to our outpatient clinic for exertional dyspnea and persistent wheezing. There were no other respiratory or systemic symptoms over the past three months, and a psychological component was suspected. Spirometry with flow-volume evaluation and bronchoscopy were the key elements to establish the diagnoses and provide treatments. Once the diagnosis of asthma was confirmed, the combination of the anti-inflammatory corticosteroid fluticasone and the rapid-acting bronchodilator formoterol in a single inhaler effectively controlled the patient's symptoms, confirming the favorable efficacy and safety profile which are reflected in the recommendations of the international guidelines.
  
  
  
  In this paper we describe the clinical investigations and interventions that eventually confirmed a diagnosis of asthma complicated by an idiopathic tracheal stenosis and led to effective treatment of the patient. Awareness of fixation error may avoid misdiagnosis in patients with respiratory disease and a complicated history at presentation.
authors.affiliation: Respiratory Unit, ASST Santi Paolo e Carlo, Milan, Italy.|Dipartimento Scienze della Salute, Università degli Studi di Milano, Milan, Italy.
authors.forename: Fabiano
authors.initials: F
authors.lastname: Di Marco
authors.affiliation: Respiratory Unit, ASST Santi Paolo e Carlo, Milan, Italy.|Dipartimento Scienze della Salute, Università degli Studi di Milano, Milan, Italy.|Casa di Cura del Policlinico, Dipartimento di Scienze Neuroriabilitative, Milan, Italy.
authors.forename: Giuseppe Francesco
authors.initials: GF
authors.lastname: Sferrazza Papa
authors.affiliation: Dipartimento Scienze della Salute, Università degli Studi di Milano, Milan, Italy.|Lung Unit, Ospedale L. Sacco-ASST Fatebenefratelli Sacco, Via G.B. Grassi, 74, 20157 Milan, Italy.
authors.forename: Dejan
authors.initials: D
authors.lastname: Radovanovic
authors.affiliation: Dipartimento Scienze della Salute, Università degli Studi di Milano, Milan, Italy.|Lung Unit, Ospedale L. Sacco-ASST Fatebenefratelli Sacco, Via G.B. Grassi, 74, 20157 Milan, Italy.
authors.forename: Pierachille
authors.initials: P
authors.lastname: Santus
keywords: Asthma; Dyspnea; Fluticasone/formoterol; Pulmonary function tests; Tracheal stenosis