Test 3 Wk11: 11 Respiratory Fungal Infections - Shah Flashcards
North American Blastomycosis Causative Agent:
B.dermatitidis
B.dermatitidis is — in nature
dimorphic
B.dermatitidis location
Ohio & Mississippi River
valleys, the Great Lakes,
and in the southeast
Clinical Presentation
Blastomycosis : B.Dermatitidis
Flu like symptoms
B.Dermatitidis Acute pulmonary
Acute pulmonary: lobar
segmental consolidation,
Mimics bacterial pneumonia .
B.Dermatitidis Chronic pulmonary
Chronic pulmonary lobar infiltrates
Mimics tuberculosis or lung
cancer
— Can disseminate to skin & bone in immunocompromised patients
B.Dermatitidis
B.Dermatitidis is acquired by
acquired by inhaling spores:
dissemination Suppurative
granulomatous;
— often misdiagnosed are carcinoma
B.Dermatitidis
Diagnosis & Treatment :
B.Dermatitidis
KOH preparation:
Sputum, BAL, lung tissue, skin biopsy,
B.Dermatitidis Yeast form is
Yeast form is large (8-12 um), round, thick walled and
hyaline
Histoplasmosis:
H. capsulatum
H. capsulatum location
Ohio and Mississippi
river valleys in the USA.
H. capsulatum elicits — similar to —
Elicits granulomas; TB
H. capsulatum animals
birds and bats
H. capsulatum comes from soil that is
high N content
H. capsulatum forms — in the body
histocytes
H. capsulatum is
dimorphic
Histoplasmosis
clinical presentation
variable
asx in healthy; can dissiminate in immunosuppressed
Histoplasmosis
clinical presentation rare cases
Acute Respiratory Distress Syndrome
Acute respiratory distress syndrome in Histoplasmosis
10% inflammatory sequelae, such as persistent
lymphadenopathy with bronchial obstruction,
arthritis, arthralgias , or pericarditis,
Mediastinal fibrosis: ARDS Histoplasmosis
Persistent host response to
the organism may result in massive fibrosis and
constriction of mediastinal structures, including
the heart and great vessels.
H. capsulatum
Diagnosis & Treatment
Direct microscopy
Culture of blood, bone, marrow or other material
enzyme immunoassay