The symptoms and signs of acute pulmonary blastomycosis are fever, cough, and myalgias; a localized pulmonary infiltrate is seen on chest radiographs. The diagnosis is usually community-acquired bacterial pneumonia, and most patients are treated with antibiotics. Only when the infection persists is the

Severe acute pulmonary histoplasmosis

Chronic cavitary pulmonary histoplasmosis in 60-year-old man with emphysema

Figure 40-2 Pulmonary histoplasmosis.

Figure 40-3 mucosal ulceration.

Ulcerating lesion of tongue due to histoplasmosis. Lesion is identical in appearance to carcinoma of tongue

Severe acute pulmonary blastomycosis with ARDS in a 56-year-old man.

Chronic pulmonary blastomycosis showing lesion in upper lobe of right lung. Radiographic pattern may, however, be very diverse.

Figure 40-4 Pulmonary blastomycosis.

Possibility of a fungal infection considered and then appropriate diagnostic studies are undertaken. A minority of patients have severe pneumonia; these patients often progress quickly to severe hypoxemia and ARDS (Figure 40-4).

Chronic pulmonary blastomycosis can be mistaken for tuberculosis or lung cancer. The symptoms include fever, night sweats, weight loss, fatigue, dyspnea, cough, sputum production, and hemoptysis. The chest radiograph shows upper lobe cavitary infiltrates, masslike lesions, or multiple nodular lesions (see Figure 40-4). Hilar and mediastinal lymphadenopathy occur less often than with histoplasmosis.

Cutaneous lesions are the most common manifestation of disseminated blastomycosis. Classically, the lesions are nonpainful, well-circumscribed nodules or plaques that are verrucous and have punctate draining areas in the center (Figure 40-5). The lesions can also be painful ulcerations or pustular nodules. The skin lesions of blastomycosis can be mistaken for those caused by nontuberculous mycobacteria, bromide use, and pyoderma gangrenosum. Patients with skin lesions may or may not have pulmonary manifestations; in many, the pneumonia has resolved by the time the skin lesions appear. Osteoarticular blastomycosis may be contiguous to skin lesions or may occur at distant sites. The genitourinary tract is another frequent site of disseminated infection, and the prostate is the usual target organ. Prostatic nodules, with or without symptoms of prostatism, are found.

Blastomycosis is more severe in immunosuppressed patients, although it is seen much less commonly than histoplasmosis and coccidioidomycosis in patients with AIDS, transplant recipients, and patients receiving TNF antagonists. In these patients, the disease is usually disseminated to multiple organs, and severe pulmonary manifestations are also more common.

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