Updated: 12/19/2019

Pneumocystis jirovecii Pneumonia (PCP)

0%
Topic
Review Topic
0
0
N/A
N/A
Questions
7 7
0
0
0%
0%
Evidence
3 3
0
0
Topic
Snapshot
  • A 45-year-old woman presents to the clinic for a nonproductive cough of 2 weeks. She has been feeling increasingly fatigued, weak, and has had low-grade fevers. She reports that she also has shortness of breath with any physical exertion. She smokes 2 cigarettes a day. She has had 10 different sexual partners in the past month and does not use protection reliably. She has a past medical history of diabetes and reports that “something bad” was found on her labs a year ago but that she never followed-up as she had been feeling fine. On physical exam, she has diffused crackles in the lungs. Upon review of her chart, she had a positive HIV test a year ago. She is started on empiric antibiotics.
Introduction
  • Classification
    • Pneumocystis jirovecii pneumonia (previously Pneumocysis carinii pneumonia)
      • a yeast-like fungus
      • airborne transmission
  • Epidemiology
    • incidence
      • decreased since the use of prophylaxis in vulnerable populations
      • more common in developing countries
    • risk factors
      • immunodeficiency
      • HIV
      • malignancy
      • smoking
  • Pathogenesis
    • when both humoral and cellular immunity are suppressed, Pneumocystis attaches to the alveoli
    • activated alveolar macrophages without CD4+ cells are not able to fight the organisms
    • this causes hypoxemia with ↑ alveolar-arterial oxygen gradient and respiratory alkalosis
  • Associated conditions
    • HIV
  • Prevention
    • smoking cessation
    • prophylaxis with medication
      • trimethoprim-sulfamethoxazole (TMP-SMX)
      • dapsone and pyrimethamine
  • Prognosis
    • mortality is 10-20%
Presentation
  • Symptoms
    • most are asymptomatic in patients with normal immune systems
    • causes interstitial pneumonia in patients with immunosuppression
      • progressive exertional shortness of breath
      • chest pain
      • nonproductive cough
      • fever and chills
      • hemoptysis is rare
  • Physical exam
    • tachypnea, tachycardia, and fever
    • mild crackles and rhonchi in the bilateral lung fields
Imaging
  • Chest radiography
    • indication
      • all patients
    • findings
      • bilateral and diffuse infiltrates
  • Computed tomography (CT) of the chest
    • indication
      • if chest radiograph is unclear
    • findings
      • bilateral and diffuse patchy ground-glass opacities
      • pneumatoceles
Studies
  • Labs
    • ↑ lactic dehydrogenase
  • Pulmonary function tests
    • ↓ diffusion capacity of carbon monoxide < 75% predicted
    • high sensitivity
  • Histology
    • methenamine silver, Diff-Quik, or Wright stain of lung tissue
      • disc-shaped yeast
  • Making the diagnosis
    • based on lung biopsy or lavage and histology
    • lung tissue histology is needed for a definitive diagnosis
Differential
  • Cytomegalovirus (CMV) pneumonia
    • distinguishing factors
      • patients also present with pharyngitis as well as lymphadenopathy and splenomegaly
      • in HIV patients, CMV also involves the gastrointestinal tract
  • Tuberculosis
    • distinguishing factor
      • often presents with hemoptysis
Treatment
  • Management approach
    • treatment may be initiated prior to definitive diagnosis
  • Medical
    • trimethoprimsulfamethoxazole (TMP-SMX)  
      • indications
        • first-line therapy
        • prophylaxis when CD4+ count < 200 cells/mm
    • corticosteroids
      • indications
        • in HIV patients with severe cases (arterial-alveolar oxygen gradient > 35 mmHg or PaO2 < 70 mmHg)
        • always given alongside antibiotics
    • pentamidine
      • indication
        • second-line therapy if resistant to TMP-SMX
    • atovaquone
      • indication
        • second-line therapy if resistant to TMP-SMX
    • dapsone and pyrimethamine
      • indication
        • prophylaxis when CD4+ count < 200 cells/mm3
Complications
  • Acute respiratory distress syndrome
Topic Rating

Please rate topic.

Average 4.0 of 6 Ratings

 

Questions (7)
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK

(M3.ID.16.42) A 27-year-old HIV positive female presents to your office with fatigue, fever, and a non-productive cough that started 2 weeks ago. She states that she gets very tired while walking short distances. Vital signs are as follows: T 103.2 F, HR 84 bpm, BP 116/72 mmHg, RR 19 bpm. Physical examination reveals light rales in the base of of the lungs bilaterally. Chest radiography is shown in Figure A. Bronchoalveolar lavage results are shown in Figure B. An ABG is performed and reveals a PaO2 of 64 mmHg. HAART therapy and IV trimethoprim-sulfamethoxazole are initiated. What other treatment is recommended for this patient? Tested Concept

QID: 102983
FIGURES:
1

Pentamidine

0%

(0/0)

2

Rifabutin

0%

(0/0)

3

Intubation and mechanical ventilation

0%

(0/0)

4

Dapsone

0%

(0/0)

5

Corticosteroids

0%

(0/0)

M 11 C

Select Answer to see Preferred Response

(M3.ID.16.40) A 35-year-old man presents to the emergency department with a complaint of shortness of breath over the past 5 days. He has had a worsening dry cough over the past 4 weeks and has also noted a 12 lb weight loss. He was diagnosed with HIV two years ago but is unable to afford the medications he was prescribed. Vital signs are as follows: T 102.8 F, HR 78 bpm, BP 122/78 mmHg, RR 14 bpm, SpO2 96%. Physical examination is unremarkable. Chest radiography is obtained and shown in Figure A. Bronchoalveolar lavage is performed and reveals the findings in Figure B. Apart from starting HAART therapy, what other treatment is recommended for this patient? Tested Concept

QID: 102981
FIGURES:
1

Pyrimethamine and sulfadiazine

0%

(0/0)

2

Trimethoprim-sulfamethoxazole

0%

(0/0)

3

Voriconazole

0%

(0/0)

4

Amphoteracin B

0%

(0/0)

5

Rifampicin, isoniazid, pyrazinamide, and ethambutol

0%

(0/0)

M 11 C

Select Answer to see Preferred Response

(M3.ID.16.38) A 33-year-old male presents to the emergency room with fatigue and a non-productive cough that started a month ago. Review of systems is positive for chills, fevers, and dyspnea on exertion. Vital signs are as follows: T 102.7 F, HR 90 bpm, BP 124/85 mmHg, RR 16 bpm. Physical examination reveals cervical lymphadenopathy. An HIV test returns positive. Chest radiography is performed and results are shown in Figure A. Which of the following diagnostic modalities is the most appropriate for this patient? Tested Concept

QID: 102979
FIGURES:
1

Purified protein derivative (PPD)

0%

(0/0)

2

Chest CT scan

0%

(0/0)

3

Lymph node biopsy

0%

(0/0)

4

Acid-fast microscopy of sputum

0%

(0/0)

5

Fiberoptic bronchoscopy with bronchoalveloar lavage

0%

(0/0)

M 10 C

Select Answer to see Preferred Response

Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Evidence (4)
Topic COMMENTS (12)
Private Note