title: Pneumomediastinum in dermatomyositis: association with cutaneous vasculopathy.
abstract: OBJECTIVE
  To study the pathogenesis of pneumomediastinum in polymyositis/dermatomyositis (PM/DM).
  
  
  METHODS
  The clinical records of 48 patients with PM/DM were reviewed, focusing mainly on the presence of pneumomediastinum and cutaneous vasculopathy, and the chest radiographic changes. A patient with pneumomediastinum with a characteristic change in his bronchus is described in detail. Case reports of pneumomediastinum in PM/DM in English publications are reviewed.
  
  
  RESULTS
  Among the 48 patients with PM/DM, pneumomediastinum was observed as a complication in four patients with DM and none of the patients with PM. Three of the four patients with pneumomediastinum, but only six of the 44 patients without this complication, had associated cutaneous vasculopathy. There was a significant association of pneumomediastinum with cutaneous vasculopathy (p = 0.02) and younger age (p = 0.04), but not with the prevalence of lung disease. A 30 year old man (patient 1) with DM, who had interstitial pneumonitis and skin ulceration due to vasculopathy, developed pneumomediastinum. Fibreoptic bronchoscopy showed white plaques on the bronchial mucosa, which were confirmed by microscopic examination as representing subepithelial necrosis. A literature review showed 13 cases of DM but no patient with PM with pneumomediastinum.
  
  
  CONCLUSIONS
  In patient 1, bronchial necrosis due to vasculopathy was strongly suspected as being responsible for the pneumomediastinum. The results suggest that pneumomediastinum was associated not with interstitial pneumonitis but with the complication of vasculopathy appearing as skin lesions in DM.
authors.affiliation: Department of Allergy and Immunological Diseases, Tokyo Metropolitan Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8677, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kono
authors.forename: S
authors.initials: S
authors.lastname: Inokuma
authors.forename: H
authors.initials: H
authors.lastname: Nakayama
authors.forename: M
authors.initials: M
authors.lastname: Suzuki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001980:Bronchi / Q000473:pathology; D002648:Child; D003882:Dermatomyositis / Q000150:complications*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008478:Mediastinal Emphysema / Q000000981:diagnostic imaging / Q000209:etiology*; D008875:Middle Aged; D009336:Necrosis; D017445:Skin Diseases, Vascular / Q000150:complications*; D014057:Tomography, X-Ray Computed