2 kinds – Typical and Atypical
Typical – wake feeling normal, then suddenly develop a fever, productive cough
Atypical – slow, insidious onset (feel bad over few days)
Community vs. Nosocomial (hospital acquired)
If you get pneumonia in the community and it’s typical, it is Strep pneumoniae. If you get
pneumonia in the community and it is atypical, it’s mycoplasma pneumoniae.
Organisms in the hospital (nosocomial) = E coli, Pseudomonas, Staph aureus (will not get
strep pneumoniae in the hospital).
Productive cough in Typical pneumonia
Reason for productive cough in typical pneumonia: have exudate (pus) and signs of
consolidation in the lung – Slide: yellow areas with microabcesses which are consolidation
in the lung. Ie lobar pneumonia = see consolidation in lung, within alveoli, causing
consolidation. Therefore, with typical, see consolidation and pus in the lung. Physical dx’tic
tools of lung consolidation: decreased percussion, increased TVF (when the person talks,
feel vibrations in chest – if have consolidation in ie the upper left lobe, will have increased
TVF b/c it is a consolidation, compared to the other side – so, increased TVF indicates
consolidation), having an “E to A” (egophony) sign (pt says E and you hear A), whispered
pectoriloquy (pt whispers “1, 2, 3” and I will hear it very loud with the stethoscope).
Therefore, decreased percussion, increased TVF, egophony, and pectoriloquy =
What if there is a pleural effusion overlying the lung? Only thing you would have
isdecreased percussion (this separates pleural effusion from pneumonia).
They do not have a high temp and do not have productive cough b/c they are interstitial
pneumonias. They have inflammation of the interstitium – there is no exudate in the alveoli
– which is why you are not coughing up a lot, and therefore do not have signs of
consolidation. So, will not have increase TVF, “E to A”, with an atypical. Atypical pneumonia
has an insidious onset, relatively nonproductive cough, no signs of consolidation.
MCC typical pneumonia = strep pneumoniae (know the pic) – gram “+” diplococcus (aka
diplococcus) – Rx = PCN G
MCC atypical pneumonia = mycoplasma pneumoniae; 2 MCC = Chlamydia pneumoniae;
which are all interstitial pneumonias.
Bronchopneumonia: MC due to strep pneumonia, and community acquired. Lobar
pneumonia. Slide: lobar consolidation on chest x-ray – strep. Pneumonia.
a) Viral pneumonias 1) Rhinovirus = MCC common cold; they are acid labile – meaning that it won’t lead to
gastroenteritis in the stomach b/c is destroyed by the acid in the stomach. Never
will have a vaccine b/c 100 serotype.
2) RSV – MCC bronchiolitis – whenever you inflame small airways, its leads to wheezing.
This is a small airway dz and bronchiolitis is MC due to RSV and pneumonia. So,
pneumonia and bronchiolitis is MC due to RSV in children.
3) Influenza – drift and shift – have hemagglutinins, which help attach the virus to the
mucosa. Have neuraminidase bore a hole through the mucosa. Antigenic drift =
minor change/mut’n in either hemagglutinins or neuraminidase; do not need a new
vaccine; antigenic shift= major change/mut’n in either hemagglutinins or
neuraminidase need a vaccine. The vaccine is against A Ag.
b) Bacterial pneumonias
1) Chlamydia psittacosis – from birds (ie parrots, turkeys).
2) Chlamydia trachomatis – a little kid was born and a week later he was wheezing (big
time), pneumonia, increased AP diameter, tympanic percussion sounds, no fever, eyes
are crusty (both sides), weird cough – staccato condh (short coughs). He got it from his
mom’s infected cervix. (MCC conjunctivitis in 2 week = Chlamydia trachomatis).
(MC overall of conjunctivitis is inflammation of erythromycin drops).
c) Hospital-acquired gram-negative pneumonias
1) Pseudomonas – water loving bacteria, therefore see in pt in ICU when on a
RESPIRATOR. pt water unit with green productive cough with.
2) Klebsiella – famous in the alcoholic; however, alcoholic can also get strep pneumonia.
So, how will you know strep vs. Klebsiella? Alcoholic with high spiking fevers,
productive cough of MUCOID appearing sputum – the capsule of Klebsiella is very
thick. Lives in the upper lobes and can cavitate, therefore can confuse with TB.
3) Legionella – atypical cough, nonproductive cough, very sick can kill you, from water
coolers (water loving bacteria), seen in mists in groceries or at restaurants.
Example: classic atypical pneumonia, then pt had hyponatremia – this is Legionella.
Legionella just doesn’t affect the lungs, also affects the other organs such as liver dz,
interstial nephritis and knocks off the juxtaglomerlur cells, and kills the renin levels,
low aldosterone and therefore lose salt in the urine, leads to hyponatremia (low
renin levels with low aldosterone). Rx = erythromycin
The two systemic fung