Severe asthma associated with myasthenia gravis and upper airway obstruction.
An unusual association of asthma and myasthenia gravis (MG) complicated by tracheal stenosis is reported. The patient was a 35-year-old black woman with a history of severe asthma and rhinitis over 30 years. A respiratory tract infection triggered a life-threatening asthma attack whose treatment required orotracheal intubation and mechanical ventilatory support. A few weeks later, tracheal stenosis was diagnosed. Clinical manifestations of MG presented 3 years after her near-fatal asthma attack. Spirometry showed severe obstruction with no response after inhalation of 400 microg of albuterol. Baseline lung function parameters were forced vital capacity, 3.29 L (105% predicted); forced expiratory volume in 1 second (FEV1), 1.10 L (41% predicted); maximal midexpiratory flow rate, 0.81 L/min (26% predicted). FEV1 after administration of albuterol was 0.87 L (32% predicted). The patient's flow-volume loops showed flattened inspiratory and expiratory limbs, consistent with fixed extrathoracic airway obstruction. Chest computed tomography scans showed severe concentric reduction of the lumen of the upper thoracic trachea.
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Pharmacology Department, Bahia School of Medicine and Public Health, Universidade Federal da Bahia, Salvador-Bahia, Brazil. adelmir@terra.om.br
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Cruz
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D000328:Adult; D000402:Airway Obstruction / Q000209:etiology*; D001249:Asthma / Q000150:complications*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D009157:Myasthenia Gravis / Q000150:complications*; D011859:Radiography; D014132:Trachea / Q000000981:diagnostic imaging / Q000473:pathology; D014135:Tracheal Stenosis / Q000209:etiology* / Q000473:pathology