An asthmatic patient with progressive lung dysfunction: a case of misdiagnosis.

In May, 2005, a 40-year-old installer of thermohydraulic systems, who was a heavy smoker and had asthma, was referred to our hospital for progressive lung dysfunction of mixed type (Tiffeneau index 57%; forced expiratory volume in 1 s 1·73 L, 43% predicted; total lung capacity 5·75 L, 80% predicted; vital capacity 3·26 L, 64% predicted). He had a history of an acute episode of pneumonitis with asthma exacerbation and pleural effusion in March, 2005. High-resolution CT showed wandering bilateral nodular shadows, more obvious in the lower right apical lobe. Blood tests showed mild eosinophilia (11·7%; normal range 1·0–6·0), increased IgE (567 kU/L; 0–91), ESR (59 mm/h; 1–12), and C-reactive protein (31·1 mg/L; 0–5·0). All other laboratory results, including immunological markers, were within normal range. From the clinical (asthmatic and rhinitic symptoms), serological (eosinophilia), and CT (wandering bilateral nodular shadow) findings, a working diagnosis of Churg-Strauss syndrome was made. However, because of persistent eosinophilia, worsening dyspnoea, and persistent opacities on CT, the patient underwent bronchoscopy, bronchoalveolar lavage (BAL), and transbronchial biopsy (TBB).