The spectrum and significance of pleural disease in blastomycosis.

To determine the incidence and significance of pleural disease in blastomycosis, we reviewed the chest roentgenograms and medical records of 26 consecutive patients with biopsy- or culture-proved Blastomyces dermatitidis infection. Twenty-three of the 26 (88 percent) had radiographic evidence of blastomycotic pleural disease. Pleural reaction that regressed on therapy was mild (less than 1.0 cm thickening on EPA chest film) in 12. More extensive pleural thickening (1.5 to 3.0 cm) was observed in five, while four had effusions, and two had pneumothoraces. The 15 patients with mild or no visible pleural thickening were considered to have minor pleural involvement, while the 11 patients with greater than 1.5 cm pleural reaction, effusions, or pneumothoraces were considered to have major pleural disease. The ages, incidence of serious underlying disorders, and extra-thoracic dissemination were similar in both groups. Chest pain was more frequent in those with major pleural involvement (8/11 vs 4/15, p = 0.02), and their white blood cell count (14,300 +/- 1,200 c/mm3) was significantly higher than that of those with minor pleural involvement (10,600 +/- 1400, p less than 0.05). All of the patients with minor pleural disease responded to amphotericin therapy, but four of 11 (36 percent) with major pleural disease had an unfavorable outcome (relapse = two, death = two) (p = 0.02). In these patients with blastomycosis, pleural involvement was extremely common. Major pleural disease was associated with an adverse prognosis and may be an indication for prolonged therapy.