Updated: 2/9/2019

Opportunistic Mycoses

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Questions
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Evidence
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Snapshot
  • A 40-year-old woman presents to the emergency room with a week of fever, cough, and hemoptysis. She has a history of HIV and has been noncompliant with her medications and has a history of tuberculosis that was adequately treated. She reports feeling increasing fatigue. A chest CT shows nodules with a halo sign. A bronchoalveolar lavage with biopsy eventually reveals fungus with septate hyphae branching at acute angles invading into lung tissue. (Invasive aspergillosis)
Candida albicans
  • Classification
    • yeast with budding and pseudohyphae
    • germ tube formation at 37°C (diagnostic)  
    • can be part of normal flora
  • Risk factors
    • immunocompromised status
    • hospital admission, especially in the ICU
  • Clinical syndrome
    • immunocompetent hosts present with skin and mucous membrane infections
      • oral thrush
        • white plaque on the tongue that can be scraped off
      • candidal intertrigo
        • well-demarcated, erythematous, and itchy plaques in the skin folds
      • vulvovaginitis
        • thick "cottage cheese" white discharge
        • itchiness
    • immunocompromised hosts usually present with systemic disease
      • local infection is due to T-cell deficiency while systemic infection is due to neutropenia
      • esophagitis
        • dysphagia and throat pain
        • endoscopy shows white plaques along the esophagus
      • endocarditis
        • associated with IV drug users
        • fevers and a new murmur
      • disseminated/invasive candidiasis
        • fever and septic shock
  • Studies
    • definitive diagnosis requires blood or other tissue culture
    • wet mount with potassium hydroxide prep of vaginal fluid shows yeast with pseudohyphae
    • germ tube formation at 37°C 
  • Treatment
    • nystatin
      • local infections
    • azoles
      • local and systemic infections
      • first-line if the fungus is not resistant
    • echinocandins
      • systemic infections
      • first-line due to increased resistance to azoles
    • amphotericin B
      • systemic infections
      • second-line or for pregnant women
Cryptococcus neoformans
  • Classification
    • urease-positive monomorphic encapsulated yeast with 5-10 μm narrow budding
    • transmitted via inhalation and found in soil and pigeon droppings
  • Risk factors
    • immunocompromised status
    • HIV/AIDS patients
  • Clinical syndrome
    • cryptococcosis
    • cryptococcal meningitis
    • cryptococcal encephalitis
    • presents with fevers, headaches, and generalized malaise
  • Studies and imaging
    • head imaging with computed tomography (CT) or magnetic resonance imaging (MRI)
      • soap bubble lesions
      • variable enhancing lesions
      • hydrocephalus
    • detection of capsular antigen in serum or cerebrospinal fluid (CSF)
      • latex agglutination test
    • CSF studies
      • culture on Sabouraud agar
      • India ink stain shows yeast with clear halos
      • mucicarmine shows yeast with red inner capsules
  • Treatment
    • amphotericin B + flucytosine
      • for 10-14 days
    • fluconazole
      • after treatment with amphotericin B and flucytosine
      • maintenance and suppressive therapy
Aspergillus spp.
  • Classification
    • most commonly Aspergillus fumigatus
    • monomorphic fungus with septate hyphae branching at acute angles (45 degrees)
    • found in soil and decomposed material
    • transmission via inhalation of spores
  • Risk factors
    • immunocompromised status
    • hematologic malignancy
    • asthma
    • pre-existing lung disease
  • Clinical syndrome
    • invasive aspergillosis
      • invasive infection of the lung
      • causes persistent fever and cough with hemoptysis
    • aspergilloma
      • mycetoma ("fungal ball") in pre-existing cavity (i.e., tuberculosis)
      • causes cough with hemoptysis or asymptomatic
    • allergic bronchopulmonary aspergillosis (ABPA)
      • hypersensitivity reaction in patients with cystic fibrosis or asthma
      • causes bronchiectasis and eosinophilia
      • causes cough with hemoptysis, brownish black mucus plugs in expectorate, and wheezing
  • Studies and imaging
    • invasive aspergillosis
      • nodules with halo sign and cavitary lesions on computed tomography (CT)
      • pathologic examination showing invasive hyphae into tissue
      • positive cultures or serology
    • aspergilloma
      • mobile round or ovoid mass on chest CT
      • positive cultures or serology
    • ABPA
      • bronchiectasis on CT  
      • elevated eosinophils or IgE in ABPA
  • Treatment
    • invasive aspergilloma
      • voriconazole + amphotericin B
        • first-line
      • caspofungin
        • second-line
    • aspergilloma
      • surgical resection
    • ABPA
      • steroids
        • first-line
Mucormycosis
  • Classification
    • Mucor and Rhizopus spp.
      • fungi with irregular, broad, and nonseptate hyphae branching at wide or right angles
      • found in soil and decomposed material
      • transmission via inhalation of spores or direct inoculation through trauma
  • Risk factors
    • diabetic ketoacidosis
    • immunocompromised status
    • trauma or burns
  • Clinical syndrome
    • mucormycosis (rhinocerebral infection)
      • headache
      • congestion
      • sinus pressure and pain
      • black necrotic eschar on face, particular nares or palate
  • Studies and imaging
    • computed tomography (CT) shows air-fluid levels in the sinuses and bony destruction
    • biopsy of affected tissue shows nonseptate hyphae with wide-angle branching
  • Treatment
    • amphotericin B
      • first-line
    • isavuconazole
      • second-line
    • surgical debridement
      • for patients who need it, in addition to antifungals
         
Pneumocystis jiroveci
  • Classification
    • a yeast-like fungus
    • transmission via airborne
  • Risk factors
    • immunocompromised status
    • HIV
    • smoking
  • Clinical syndrome
    • interstitial pneumonia
      • progressive exertional dyspnea
      • chest pain
      • nonproductive cough
      • fever and chills
      • hemoptysis is rare
  • Imaging
    • chest radiograph will show bilateral infiltrates
    • computed tomography will show patchy ground-glass opacities sand pneumatoceles
  • Studies
    • histology with methenamine silver, Diff-Quik, or Wright stain of lung tissue
      • disc-shaped yeast
  • Treatment
    • trimethoprim-sulfamethoxazole (TMP-SMX)
      • prophylaxis (CD4+ count < 200 cells/mm3) and first-line therapy
    • corticosteroids
      • severe cases
    • pentamidine, atovaquone, or dapsone
      • second-line therapy if resistant to TMP-SMX or allergic
 

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Questions (16)
Lab Values
Blood, Plasma, Serum Reference Range
ALT 8-20 U/L
Amylase, serum 25-125 U/L
AST 8-20 U/L
Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL
Calcium, serum (Ca2+) 8.4-10.2 mg/dL
Cholesterol, serum Rec: < 200 mg/dL
Cortisol, serum 0800 h: 5-23 μg/dL //1600 h:
3-15 μg/dL
2000 h: ≤ 50% of 0800 h
Creatine kinase, serum Male: 25-90 U/L
Female: 10-70 U/L
Creatinine, serum 0.6-1.2 mg/dL
Electrolytes, serum  
Sodium (Na+) 136-145 mEq/L
Chloride (Cl-) 95-105 mEq/L
Potassium (K+) 3.5-5.0 mEq/L
Bicarbonate (HCO3-) 22-28 mEq/L
Magnesium (Mg2+) 1.5-2.0 mEq/L
Estriol, total, serum (in pregnancy)  
24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL
28-32 wk // 36-40 wks 40-220 ng/mL // 80-350 ng/mL
Ferritin, serum Male: 15-200 ng/mL
Female: 12-150 ng/mL
Follicle-stimulating hormone, serum/plasma Male: 4-25 mIU/mL
Female: premenopause: 4-30 mIU/mL
midcycle peak: 10-90 mIU/mL
postmenopause: 40-250
pH 7.35-7.45
PCO2 33-45 mmHg
PO2 75-105 mmHg
Glucose, serum Fasting: 70-110 mg/dL
2-h postprandial:<120 mg/dL
Growth hormone - arginine stimulation Fasting: <5 ng/mL
Provocative stimuli: > 7ng/mL
Immunoglobulins, serum  
IgA 76-390 mg/dL
IgE 0-380 IU/mL
IgG 650-1500 mg/dL
IgM 40-345 mg/dL
Iron 50-170 μg/dL
Lactate dehydrogenase, serum 45-90 U/L
Luteinizing hormone, serum/plasma Male: 6-23 mIU/mL
Female: follicular phase: 5-30 mIU/mL
midcycle: 75-150 mIU/mL
postmenopause 30-200 mIU/mL
Osmolality, serum 275-295 mOsmol/kd H2O
Parathyroid hormone, serume, N-terminal 230-630 pg/mL
Phosphatase (alkaline), serum (p-NPP at 30° C) 20-70 U/L
Phosphorus (inorganic), serum 3.0-4.5 mg/dL
Prolactin, serum (hPRL) < 20 ng/mL
Proteins, serum  
Total (recumbent) 6.0-7.8 g/dL
Albumin 3.5-5.5 g/dL
Globulin 2.3-3.5 g/dL
Thyroid-stimulating hormone, serum or plasma .5-5.0 μU/mL
Thyroidal iodine (123I) uptake 8%-30% of administered dose/24h
Thyroxine (T4), serum 5-12 μg/dL
Triglycerides, serum 35-160 mg/dL
Triiodothyronine (T3), serum (RIA) 115-190 ng/dL
Triiodothyronine (T3) resin uptake 25%-35%
Urea nitrogen, serum 7-18 mg/dL
Uric acid, serum 3.0-8.2 mg/dL
Hematologic Reference Range
Bleeding time 2-7 minutes
Erythrocyte count Male: 4.3-5.9 million/mm3
Female: 3.5-5.5 million mm3
Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/h
Female: 0-20 mm/h
Hematocrit Male: 41%-53%
Female: 36%-46%
Hemoglobin A1c ≤ 6 %
Hemoglobin, blood Male: 13.5-17.5 g/dL
Female: 12.0-16.0 g/dL
Hemoglobin, plasma 1-4 mg/dL
Leukocyte count and differential  
Leukocyte count 4,500-11,000/mm3
Segmented neutrophils 54%-62%
Bands 3%-5%
Eosinophils 1%-3%
Basophils 0%-0.75%
Lymphocytes 25%-33%
Monocytes 3%-7%
Mean corpuscular hemoglobin 25.4-34.6 pg/cell
Mean corpuscular hemoglobin concentration 31%-36% Hb/cell
Mean corpuscular volume 80-100 μm3
Partial thromboplastin time (activated) 25-40 seconds
Platelet count 150,000-400,000/mm3
Prothrombin time 11-15 seconds
Reticulocyte count 0.5%-1.5% of red cells
Thrombin time < 2 seconds deviation from control
Volume  
Plasma Male: 25-43 mL/kg
Female: 28-45 mL/kg
Red cell Male: 20-36 mL/kg
Female: 19-31 mL/kg
Cerebrospinal Fluid Reference Range
Cell count 0-5/mm3
Chloride 118-132 mEq/L
Gamma globulin 3%-12% total proteins
Glucose 40-70 mg/dL
Pressure 70-180 mm H2O
Proteins, total < 40 mg/dL
Sweat Reference Range
Chloride 0-35 mmol/L
Urine  
Calcium 100-300 mg/24 h
Chloride Varies with intake
Creatinine clearance Male: 97-137 mL/min
Female: 88-128 mL/min
Estriol, total (in pregnancy)  
30 wks 6-18 mg/24 h
35 wks 9-28 mg/24 h
40 wks 13-42 mg/24 h
17-Hydroxycorticosteroids Male: 3.0-10.0 mg/24 h
Female: 2.0-8.0 mg/24 h
17-Ketosteroids, total Male: 8-20 mg/24 h
Female: 6-15 mg/24 h
Osmolality 50-1400 mOsmol/kg H2O
Oxalate 8-40 μg/mL
Potassium Varies with diet
Proteins, total < 150 mg/24 h
Sodium Varies with diet
Uric acid Varies with diet
Body Mass Index (BMI) Adult: 19-25 kg/m2
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(M1.MC.9) A 47-year-old male with HIV presents to the emergency department with a 2-week history of dyspnea on exertion. He states that over the past week his symptoms seemed to have worsened and he now is experiencing a non-productive cough and low grade fever as well. He also admits that he recently stopped taking an antibiotic that was prescribed by his infectious disease physician because he could not tolerate the side effects. A chest radiograph is obtained which is demonstrated in Figure F and an arterial blood gas demonstrates a PO2 of 70%. Further labs are obtained and are notable for a CD4+ count of 184 and an LDH of 340. Which of the following figures (A-E) correctly demonstrates the causative organism of this patient's infection? Review Topic

QID: 103607
FIGURES:
1

Figure A

52%

(101/196)

2

Figure B

11%

(21/196)

3

Figure C

15%

(30/196)

4

Figure D

11%

(21/196)

5

Figure E

10%

(20/196)

M1

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(M1.MC.74) A 55-year-old man, who underwent a kidney transplant 2 years ago, presents in septic shock. He is compliant with his immunosuppressive therapy. He does not use any drugs and is sexually active with one male partner. His complete blood count returns as follows: Hemoglobin: 13.7 g/dL, white blood cell count: 4000 cells/microliter, platelets 250,000 cells/microliter. Of note, from his differential: neutrophils: 10%, lymphocytes: 45%, and monocytes: 7%. His basic metabolic profile is notable for a creatinine remaining at his baseline of 0.9 mg/dL. The patient is started on broad spectrum antibiotics, but his condition does not improve. Fungal blood cultures are obtained and grow Candida species. Which of the following was the most-likely predisposing factor? Review Topic

QID: 106651
1

Defective IL-2 receptor

0%

(0/7)

2

Decreased phagocytic cell count

71%

(5/7)

3

HIV infection

29%

(2/7)

4

Failure to take suppressive trimethoprim/sulfamethoxazole therapy

0%

(0/7)

5

Renal failure

0%

(0/7)

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(M1.MC.34) A 43-year-old HIV positive male presents with signs and symptoms concerning for a fungal infection. He is currently not on antiretrovirals and his CD4 count is 98. Which of the following candidal infections could be seen in this patient but would be very rare in an immunocompetent host? Review Topic

QID: 101493
1

Oral thrush

24%

(4/17)

2

Vaginitis

0%

(0/17)

3

Intertrigo

12%

(2/17)

4

Esophagitis

41%

(7/17)

5

Endocarditis

12%

(2/17)

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(M1.MC.14) A 31-year-old female undergoing treatment for leukemia is found to have a frontal lobe abscess accompanied by paranasal swelling. She additionally complains of headache, facial pain, and nasal discharge. Biopsy of the infected tissue would most likely reveal which of the following? Review Topic

QID: 101473
1

Yeast with pseudohyphae

12%

(30/260)

2

Budding yeast with a narrow base

13%

(35/260)

3

Septate hyphae

17%

(43/260)

4

Irregular non-septate hyphae

47%

(121/260)

5

Spherules containing endospores

10%

(25/260)

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(M1.MC.188) A 50-year-old HIV-positive male presents to the ER with a two-day history of fever and hemoptysis. Chest radiograph shows a fibrocavitary lesion in the right middle lobe. Biopsy of the afflicted area demonstrates septate hyphae that branch at acute angles. Which of the following is the most likely causal organism? Review Topic

QID: 101647
1

Mycobacterium tuberculosis

5%

(1/19)

2

Candida albicans

5%

(1/19)

3

Pneumocystis jeroveci

5%

(1/19)

4

Aspergillus fumigatus

84%

(16/19)

5

Naegleria fowleri

0%

(0/19)

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