A case of chest tightness variant asthma : the usefulness of fractional exhaled nitric oxide as a marker for the diagnosis and clinical improvement

A 50-year-old woman was referred to our hospital for further examination of severe constricting pain at the right-side dominant anterior chest. She had medical history of outgrown childhood asthma and allergies to several animals. Chest auscultation revealed no wheezes, rhonchi and other crackles. Laboratory findings showed an eosinophilia and an elevation of total immunoglobulin E. The results of an electrocardiogram, a chest X-ray and a chest CT were unremarkable. A fractional exhaled nitric oxide value remarkably elevated, but the abnormalities in pulmonary function test were modest. Her chest pain was ameliorated after inhaling procaterol. Based on these findings, a diagnosis of chest tightness variant asthma was formulated, and we started treatment with inhaled corticosteroid / long acting β2 agonist. At two-weeks after treatment, her symptom markedly improved and a fractional exhaled nitric oxide value decreased, which led to a definitive diagnosis of chest tightness variant asthma. A fractional exhaled nitric oxide value further decreased to the normal range in consistent with symptom disappearance at 10-months after treatment, indicating the usefulness of fractional exhaled nitric oxide as a promising marker for the diagnosis and clinical improvement of chest tightness variant asthma. J. Med. Invest. 68 : 389-392, August, 2021