Vocal cord dysfunction is a rare clinical picture. It is labeled as a sudden and threatening dyspnea. Patients with VCD may also present cough, hoarseness, wheezing, and chest tightness, but an inspiratory stridor is the most common symptom. For this reason, such patients are often misdiagnosed with refractory asthma, because of poor response to steroids and bronchodilators. Diagnosis is suspected on clinical grounds and is confirmed with laryngoscopy. The therapy consists of education, speech therapy and if necessary psychotherapy. The purpose of the investigators' study is to characterize children, adolescents, and young adults with VCD, and the evaluation of predictors as atopy, bronchial hyperresponsiveness, and psychiatric features.