title: Corticosteroid-induced myopathy mimicking therapy-resistant asthma.
abstract: BACKGROUND
  Therapy-resistant asthma is an important clinical problem. However, before considering asthma truly therapy resistant, it is essential to exclude diagnoses that may masquerade as therapy-resistant asthma, such as vocal cord dysfunction and recurrent aspiration, as well as factors related to loss of asthma control, including poor compliance, exposure to allergens, and sinusitis. Corticosteroid-induced myopathy may be an unrecognized but potentially important consideration in both settings.
  
  
  OBJECTIVE
  To describe a patient with corticosteroid-induced myopathy complicating recurrent exacerbations of asthma, which presented with persistently reduced airflow that mimicked therapy-resistant asthma.
  
  
  METHODS
  A 20-year-old Japanese woman with severe intractable asthma who had a history of near-fatal attacks was admitted with recurrent asthma exacerbations that required long-term systemic corticosteroids.
  
  
  RESULTS
  Wheezing episodes decreased but airflow limitation persisted, which was due to not only uncontrolled asthma but also corticosteroid-induced myopathy. Myopathy prevented the adequate use of inhalers, which in turn complicated the tapering of corticosteroids, leading to a vicious cycle. Careful and gradual reduction of corticosteroid dose, while continuing systemic administration of nonsteroidal antiasthma medications, resulted in a resolution of clinical and electromyographic signs of myopathy and pulmonary function abnormalities.
  
  
  CONCLUSIONS
  Corticosteroid-induced myopathy can masquerade as therapy-resistant asthma and can cause poor asthma control.
authors.affiliation: Department of Respiratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Akio
authors.initials: A
authors.lastname: Niimi
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Minakuchi
authors.forename: Hisako
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Koichi
authors.initials: K
authors.lastname: Shimizu
authors.forename: Kazuo
authors.initials: K
authors.lastname: Chin
authors.forename: Michiaki
authors.initials: M
authors.lastname: Mishima
mesh_terms: D000305:Adrenal Cortex Hormones / Q000009:adverse effects* / Q000627:therapeutic use; D000328:Adult; D001249:Asthma / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D003937:Diagnosis, Differential; D004351:Drug Resistance; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D009135:Muscular Diseases / Q000139:chemically induced* / Q000175:diagnosis; D010366:Peak Expiratory Flow Rate; D013147:Spirometry
chemical_list: D000305:Adrenal Cortex Hormones; D007073:Immunoglobulin E