Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Key Features +++ Essentials of Diagnosis ++ Residence in, or travel to, an endemic area In immunocompetent patients, most often a self-limited flu-like illness; acute pneumonia occurs in a minority of cases Diagnosis by culture of specimens from bronchoscopy, skin, or other tissue, or antigen detection +++ General Considerations ++ Blastomyces dermatitidis is causative fungus Found in soil primarily in the Mississippi and Ohio River valleys, additional southeastern and south central states, and the states bordering the Great Lakes Transmission is by inhalation of spores Subclinical disease is common Infection rates are similar in both sexes +++ Clinical Findings +++ Symptoms and Signs ++ Primary infection is often unrecognized or associated with Cough with purulent sputum Chest pain Headache Weight loss Night sweats Fever Infection is most often self-limited in immunocompetent patients However, an indolent progressive pulmonary disease occurs after an incubation period of 20–100 (median 45) days in some patients Cutaneous lesions Usually represent disseminated disease Slowly progressive Ulcerative with a sharp, heaped-up border or verrucous appearance Bone disease resembles other forms of chronic osteomyelitis Lytic skull lesions in children are typical, but long bones, vertebrae, and the pelvis may be involved Extrapulmonary disease occurs in 25–40% of patients with progressive disease +++ Differential Diagnosis ++ Acute viral, bacterial, or mycoplasmal infections Tuberculosis Histoplasmosis Coccidioidomycosis Cancer +++ Diagnosis +++ Laboratory Findings ++ An initial suppurative response is followed by an increase in mononuclear cells and subsequent formation of noncaseating granulomas Diagnosis requires isolation or visualization of the fungus Pulmonary specimens (sputum, tracheal aspirates, or lung biopsy) may be positive using conventional or fungal cell wall stains Budding yeasts have refractile thick walls and are very large and distinctive (figure-of-eight appearance) Sputum specimens are positive in more than 80% of cases and in almost all bronchial washings Skin lesions are positive in 80–100% An ELISA antigen detection method Readily detects Blastomyces antigen in serum, urine, and lung lavage fluids There is cross-reactivity with histoplasmosis +++ Imaging ++ Radiographic lobar consolidation and fibronodular interstitial and alveolar infiltrates are typical in cases with progressive pneumonia; effusions, hilar nodes, and cavities are less common Miliary patterns also occur with acute infection Cavities and fibronodular infiltration Can develop in the upper lobes in patients with chronic disease similar to those seen in tuberculosis However, these lesions rarely caseate or calcify +++ Treatment ++ For CNS infection or moderately severe or life-threatening blastomycosis (especially if immunocompromised), Lipid formulation of amphotericin B (3–5 mg/kg intravenously) for 1–2 weeks or until improved Followed by oral itraconazole (5–10 mg/kg/d; divided into two doses) for 6 months Mild to moderate blastomycosis is often treated with oral itraconazole alone for 6–12 months Bone disease may ... Your Access profile is currently affiliated with [InstitutionA] and is in the process of switching affiliations to [InstitutionB]. Please select how you would like to proceed. Keep the current affiliation with [InstitutionA] and continue with the Access profile sign in process Switch affiliation to [InstitutionB] and continue with the Access profile sign in process Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Error: Incorrect UserName or Password Username Error: Please enter User Name Password Error: Please enter Password Sign in Forgot Password? Forgot Username? Download the Access App: iOS | Android Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free profile for additional features.