Background:
Adult onset Still disease (AOSD) is a rare condition characterized by elevated fever along with arthritic symptoms, elevated polymorphonuclear neutrophil count, evanescent rash, and hyperferritinemia. Diagnosis can be made only after have ruled out more frequent conditions, and Yamagouchi or Fautrel criteria should be applied. Parenchimal lung involvement (PLI) is present in less than 5% of AOSD cases and ranges from aspecific reticular interstitial opacities to life threatening conditions, such as acute respiratory distress syndrome (ARDS).
Case:
We report the case of a 59 years old man who was referred to our ward because of high fever treated as a pneumonia with antibiotic but not responding to medical treatment, and findings suggestive of interstitial lung disease prevalent in the lower zone on high resolution computed tomography (HRCT). AOSD was diagnosed when the diagnostic Yamaguchi criteria were fulfilled and our suspect was confirmed by the rheumatologist; the patient was then successfully treated with corticosteroids.
Conclusions:
PLI in AOSD is very rare but must be considered among differential diagnosis in patients with high fever and aspecific interstial parenchimal lung involvement.