<unk>  is caused by the dimorphic microfungus Blastomyces dermatitidis, a member of the phylum Ascomycota in the family Ajellomycetaceae. It has been recognised as the asexual state of Ajellomyces dermatitidis. In endemic areas, the fungus lives in soil and rotten wood near lakes and rivers. Although it has never been directly observed growing in nature, it is thought to grow there as a cottony white mold, similar to the growth seen in artificial culture at 25 °C. The moist, acidic soil in the surrounding woodland harbors the fungus. Spectrum of disease<unk>  manifests as a primary lung infection in about 70% of cases. The onset is relatively slow and symptoms are suggestive of pneumonia, often leading to initial treatment with antibacterials. Occasionally, if a lesion is seen on X-ray in a cigarette smoker, the disease may be misdiagnosed as carcinoma, leading to swift excision of the pulmonary lobe involved. Upper lung lobes are involved somewhat more frequently than lower lobes. If untreated, many cases progress over a period of months to years to become disseminated<unk> . In these cases, the large Blastomyces yeast cells translocate from the lungs and are trapped in capillary beds elsewhere in the body, where they cause lesions. The skin is the most common organ affected, being the site of lesions in approximately 60% of cases. The signature image of<unk>  in textbooks is the indolent, verrucous or ulcerated dermal lesion seen in disseminated disease. Osteomyelitis is also common (12–60% of cases). Other recurring sites of dissemination are the genitourinary tract (kidney, prostate, epididymis; collectively ca. 25% of cases) and the brain (3–10% of cases). An uncommon but very dangerous type of primary<unk>  manifests as acute respiratory distress syndrome (ARDS); for example, this was seen in 9 of 72<unk>  cases studied in northeast Tennessee. Such cases may follow massive exposure, e.g., during brush clearing operations. The fatality rate in the ARDS cases in the Tennessee study was 89%, while in non-ARDS cases of pulmonary<unk> , the fatality rate was 10%.
Blastomycosis
Chromoblastomycosis
Actinomycosis
Basidiobolomycosis
Botryomycosis
Conidiobolomycosis
Talaromycosis
Dermatomycosis