Endemic fungal infections: Histoplasmosis, (Para)Coccidioidomycosis, Blasto (mechanism of disease)

This is a flowchart on the endemic fungal infections, including histoplasmosis, coccidioidomycosis, paracoccidioidomycosis, and blastomycosis, covering the etiology, pathophysiology, and manifestations.
ADDITIONAL TAGS:
Risk factors / SDOH
Cell / tissue damage
Structural factors
Medicine / iatrogenic
Infectious / microbial
Biochem / metabolic
Immunology / inflammation
Signs / symptoms
Tests / imaging / labs
Environmental / exposure
Hereditary / genetic
Smooth muscle physiology
Pathophysiology
Etiology
Manifestations
Endemic fungal infections
Pneumonia and disseminated systemic infection with …
Histoplasma capsulatum: Histoplasmosis
Coccidioides immitis,
Coccidioides posadasii:
Coccidioidomycosis
(valley fever)
Paracoccidioides brasiliensis,
Paracoccidioides lutzii:
Paracoccidioidomycosis
Blastomyces dermatitidis:
Blastomycosis
Living/travel in endemic areas: Mississippi and the Ohio river valley
Exposure to bird / bat droppings in endemic areas via activities like spelunking, cave exploration
Immunosuppression (AIDS, medication, hereditary, etc)
Living/travel in endemic areas: California, Southwestern USA
Soil/dust exposure (e.g., during windstorms, earthquakes, archeological explorations)
Living/travel in endemic areas: South and Central America
♂ ♀ (15-fold difference)
Living/travel in endemic areas: Southeastern, Central, Eastern, and the Great Lakes region of USA
Map from the Centers for Disease Control and Prevention
Asymptomatic
Flu-like illness: fever, weight loss, erythema nodosum, hepatosplenomegaly, lymphadenopathy, nonproductive cough
Ulcerative oral lesion (palatal, tongue ulcers)
CXR: diffuse nodular densities, focal infiltrate or cavity, or LAD
Best initial test: positive urine and serum polysaccharide antigen test
Silver stain of biopsy or bronchoalveolar lavage showing
Macrophages filled with yeast cells that measure 1-5 μm, size RBC
Flu-like illness or pneumonia: fever, cough, night sweats, anorexia, chest pain, and dyspnea
CNS: meningitis
CXR: normal or infiltrates/lymphadenopathy/pleural effusion
Sputum, wound exudate, joint effusion → KOH, silver stain, or culture showing: large spherules containing endospores, size RBC
Skin: erythema nodosum (desert bumps)
Joints: arthralgia (desert rheumatism)
Bone: multiple osteolytic lesions
Asymptomatic
Painful nasal, pharyngeal, and laryngeal mucosal ulcerations
Smear (with KOH/calcofluor stain) or tissue biopsy (with silver/PAS stain): budding yeast with “captain's wheel” formation, size RBC
Lymphadenopathy (usually cervical)
Can disseminate → extrapulmonary manifestations; looks like →
Pneumonia: cough, dyspnea, tachycardia, fever
Sputum, urine, or body fluids → KOH first, then confirmatory culture: yeast form (at = 37°C), broad-based buds, size = RBC
Skin: verrucous lesions and granulomatous nodules (looks like SCC)
Bone: osteolytic lesions (in the ribs, vertebrae, and long bones)
Genitourinary involvement: prostatitis, orchitis, epididymitis
CNS lesions: meningitis, epidural/intracranial abscesses