Pulmonary Blastomycosis

Abstract

Blastomycosis is a rare but important fungal infection diagnosed primarily in the south central and midwestern United States but also in the American and Canadian borders of the Great Lakes. Epidemics of infection related to point-source exposure include patients of all ages and both sexes, but endemic cases are usually in young to middle-aged adults, with more men than women reported. Pneumonia is the most common manifestation and the lung is almost always the organ initially infected. The lung manifestations range from illness that mimics acute bacterial pneumonia to chronic, destructive lung disease appearing like tuberculosis or lung cancer. Extrapulmonary disease can occur with or without concomitant lung disease. In descending order, cutaneous, osseous, prostatic, and central nervous system involvements are the most frequent manifestations of extrapulmonary blastomycosis. Amphotericin B is curative, but, because of toxicity, oral azole agents have replaced amphotericin B as therapy for less than overwhelming blastomycosis. Itraconazole is now considered to be the agent of choice with fluconazole, voriconazole, and posaconazole having a role in selected patients. In a patient with life-threatening or central nervous system blastomycosis amphotericin B should be given, at least initially.

Retrospective Comparison of the Efficacy of Fluconazole or Itraconazole for the Treatment of Systemic Blastomycosis in Dogs

“…Therefore, treatment with itraconazole is based on small open-label studies and anecdotal experience. 13,14 Two studies suggested that fluconazole was not as efficacious as itraconazole in the treatment of human blastomycosis, 15,16 therefore the use of fluconazole has remained limited in this disease. In 91 dogs treated with itraconazole at either 5 or 10 mg/kg/d, 75% responded to a 60-day itraconazole course while 25% died.…”

Endemic Fungal Infections in Inflammatory Bowel Disease Associated with Anti-TNF Antibody Therapy

“…84,87,98 In moderate to severe disease, initial therapy with amphotericin B is followed by consolidative therapy with itraconazole. 84,99 Amphotericin B is used in the treatment of severe blastomycosis and for cases with CNS involvement. 84,100 A large series from Mississippi showed an 86% response rate to treatment and a relapse rate of 4%.…”

Blastomyces dermatitidis: Antibody Detection in Sera from Dogs with Blastomycosis with Yeast Lysate Antigens Produced from Human and Dog Isolates

“…The disease may be self-resolving or it may exist as an acute or chronic state in the pulmonary tissue, where it may be misdiagnosed as tuberculosis or some other pulmonary disease. If the disease is not diagnosed or untreated while in the lungs, it may become invasive and disseminate to other organs including the skin, eyes (ocular involvement in dogs), bones, and, possibly, the central nervous system where fatal meningitis may develop [3–7]. …”