Difference between revisions of "Acute infectious pneumonia"

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#redirect [[Pneumonia#Acute_infectious_pneumonia]]
'''Acute infectious pneumonia''' is a common type of [[pneumonia]]. It is usually diagnosed clinically and uncommonly biopsied.
 
==General==
Clinical features:
*[[Dyspnea]].
*Chest pain.
*Fever.
 
It is seen by pathologists at [[autopsy]] from time-to-time, and in advanced [[lung cancer]].
 
===Etiology===
Most common cause:
*''Streptococcus pneumoniae''.<ref name=Ref_PBoD8_711>{{Ref PBoD8|711}}</ref>
 
The top three community acquired (acute) pneumonia:<ref name=pmid12239229>{{Cite journal  | last1 = Nicolau | first1 = D. | title = Clinical and economic implications of antimicrobial resistance for the management of community-acquired respiratory tract infections. | journal = J Antimicrob Chemother | volume = 50 Suppl S1 | issue =  | pages = 61-70 | month = Sep | year = 2002 | doi =  | PMID = 12239229 }}</ref>
*''Streptococcuc pneumonia''.
*''Haemophilus influenzae''.
*''Moraxella catarrhalis''.
 
Other community acquired pneumonia:<ref name=Ref_PBoD8_711>{{Ref PBoD8|711}}</ref>
*S. aureus.
*Legionaella pneumophila.
*Klebsiella pneumoniae.
*[[Pseudomonas]].
 
Hospital-acquired pneumonia:<ref name=Ref_PBoD8_711>{{Ref PBoD8|711}}</ref>
*Gram-negative rods.
*''Staphylococcus aureus''.
 
==Radiologic correlate==
*Air space disease.
 
==Gross pathology==
*Consolidation (the lung parenchyma is firm) - best appreciated by running a finger over the cut surface of the lung with a small-to-moderate amount of pressure.
 
Bronchopneumonia:
*Classically yellow-white centered on the bronchi.<ref>{{Ref AoGP|93}}</ref>
 
Lobar pneumnia is classically described in four stages:<ref>{{Ref AoGP|92}}</ref><ref>URL: [http://www.histopathology-india.net/Lobar_Pneumonia.htm http://www.histopathology-india.net/Lobar_Pneumonia.htm]. Accessed on: 27 February 2012.</ref>
#Congestion - day 1-2.
#Red hepatization - day 2-4.
#Gray hepatization - day 4-6.
#Resolution - day 6+.
 
Note:
*The stages of lobar pneumonia is considered more-or-less historical.  In the age of antibiotics, lobar pneumonia is uncommon.
 
==Microscopic==
Features:
*Alveoli packed with [[PMN]]s.
*+/-Clusters of bacteria - small dots or rods.
*+/-Abscess formation.
**Lung abscess = destruction of parenchyma + [[PMN]]s.<ref name=Ref_AoGP95>{{Ref AoGP|95}}</ref>
 
DDx:
*[[Aspiration pneumonia]] - aspirated material, usually lack microorganisms.
 
===Images===
<gallery>
Image:Pneumonia_alveolus.jpg | Normal alveoli & pneumonia. (WC)
</gallery>
<gallery>
Image: Acute pneumonia -- low mag.jpg | AP - low mag.  (WC)
Image: Acute pneumonia -- intermed mag.jpg | AP - intermed. mag. (WC)
Image: Acute pneumonia - alt -- intermed mag.jpg | AP - intermed. mag. (WC)
Image: Acute pneumonia -- high mag.jpg | AP - high mag. (WC)
Image: Acute pneumonia -- very high mag.jpg | AP - very high mag. (WC)
</gallery>
 
==Stains==
*Gram stain -- to type the bacteria.
 
==See also==
*[[Pneumonia]].
*[[Acute pneumonia]].
 
==References==
{{Reflist|1}}


[[Category:Diagnosis]]
[[Category:Diagnosis]]
[[Category:Medical lung diseases]]

Latest revision as of 16:01, 13 February 2016

Acute infectious pneumonia is a common type of pneumonia. It is usually diagnosed clinically and uncommonly biopsied.

General

Clinical features:

It is seen by pathologists at autopsy from time-to-time, and in advanced lung cancer.

Etiology

Most common cause:

  • Streptococcus pneumoniae.[1]

The top three community acquired (acute) pneumonia:[2]

  • Streptococcuc pneumonia.
  • Haemophilus influenzae.
  • Moraxella catarrhalis.

Other community acquired pneumonia:[1]

  • S. aureus.
  • Legionaella pneumophila.
  • Klebsiella pneumoniae.
  • Pseudomonas.

Hospital-acquired pneumonia:[1]

  • Gram-negative rods.
  • Staphylococcus aureus.

Radiologic correlate

  • Air space disease.

Gross pathology

  • Consolidation (the lung parenchyma is firm) - best appreciated by running a finger over the cut surface of the lung with a small-to-moderate amount of pressure.

Bronchopneumonia:

  • Classically yellow-white centered on the bronchi.[3]

Lobar pneumnia is classically described in four stages:[4][5]

  1. Congestion - day 1-2.
  2. Red hepatization - day 2-4.
  3. Gray hepatization - day 4-6.
  4. Resolution - day 6+.

Note:

  • The stages of lobar pneumonia is considered more-or-less historical. In the age of antibiotics, lobar pneumonia is uncommon.

Microscopic

Features:

  • Alveoli packed with PMNs.
  • +/-Clusters of bacteria - small dots or rods.
  • +/-Abscess formation.
    • Lung abscess = destruction of parenchyma + PMNs.[6]

DDx:

Images

Stains

  • Gram stain -- to type the bacteria.

See also

References

  1. 1.0 1.1 1.2 Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 711. ISBN 978-1416031215.
  2. Nicolau, D. (Sep 2002). "Clinical and economic implications of antimicrobial resistance for the management of community-acquired respiratory tract infections.". J Antimicrob Chemother 50 Suppl S1: 61-70. PMID 12239229.
  3. Rose, Alan G. (2008). Atlas of Gross Pathology with Histologic Correlation (1st ed.). Cambridge University Press. pp. 93. ISBN 978-0521868792.
  4. Rose, Alan G. (2008). Atlas of Gross Pathology with Histologic Correlation (1st ed.). Cambridge University Press. pp. 92. ISBN 978-0521868792.
  5. URL: http://www.histopathology-india.net/Lobar_Pneumonia.htm. Accessed on: 27 February 2012.
  6. Rose, Alan G. (2008). Atlas of Gross Pathology with Histologic Correlation (1st ed.). Cambridge University Press. pp. 95. ISBN 978-0521868792.