Lung infections galore - I am always getting these wrong!

[nope80]

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I need help with this one - are there any hints/clinical clues that people use to differentiate or particularly narrow in on the lung infections. I am literally getting every single on of these wrong and just can't seem to differentiate between all the viruses, bacterias, fungi, etc based on the questions in UWORLD. Does anyone have any clues or any thought process they go through to eliminate? I really really appreciate any help or advice. I need it 😳

 

[Depakote]

General hints (not 100% accurate, apply common sense), but these seem to be the big give-aways:

If it's a neonate, they probably picked it up on the way out: group B strep- (gram +), e. coli (gram -), keep an eye out for chlamydia trachomonotis

If it's an infant, probably RSV

Pretty much anyone can get strep. pneumo "gram positive diplococci" or "lancet-shaped" is the key here.

Mycoplasma- that young adult age range (college kids and military recruits), when people are crowded together, same factor for meningitis spread. Horrible x-ray, disease isn't too bad. Nonproductive cough. Cold agglutinins/raynauds phenomena would seal the deal. Does NOT show up on gram stain. Immunity is Ig mediated, just like the autoimmune hemolysis.

Legionella- intracellular bug, likes to spread via aerosol so you'll probably see something about an air conditioner, mist, etc. Atypical pneumonia like mycoplasma but you don't get the cold agglutinins. You do have watery upper airway secretions (which is different), associate the watery secretions with the watery means of distribution.

Chlamydia Psittaci- bird handlers

TB- reactivation is in the apex. primary (ghon focus) tends to be lower. You can have a great immune response to the initial infx, but consider the bugs walled off, not gone. They can reactivate in times of immunosupression.

Cryptococcus- opportunistic pathogen, esp in HIV. India Ink stain. Can become meningitis

Cocciodies- Pulm infx, disseminates. Dusty environments. American southwest. Can infx healthy host.

Histoplasma- Lung infx that disseminates, yeast form in macrophages. Central US. Can infx healthy host. Bat Poop.

Blastomyces- Lung infx that disseminates, likes the skin. Broad-based bud. Eastern US.

Pneumocystis- AIDS asc pneumonia w/ T-Cell count below 200. Silver Stain. Give TMP-SMX.

Aspergillus- Usually immunosupressed pts. multiple flavors (aspergilloma, attached to existing mucus plugs), hyphae like to punch through vessels-> hemoptysis.

Candida- Oral- normal in babies, if seen in adult, worry about immunosupression or other cause. (HIV, Diabetes, steroids). Esophageal candida is AIDs defining.


Other fun stuff.

Post Influenza lung infx, think Staph Aureus

Pneumonia in alcoholic, think Klebsiella

Cystic Fibrosis/Kartageners/Ventilator pts= Pseudomonas

Aspiration pneumonia- consider staph + oral flora + anaerobes

Air Fluid Level = Abscess - could be aspiration of bugs above







That's what I can think of for now...

 

[ZagDoc]

Also keep your eye out for buzz words, but know what the buzz words mean. The question will never say "red currant jelly sputum" (Klebsiella) but it will describe what red currant jelly would look like. Massive hemoptysis = Aspergillus. Temperature/Heart rate dissociation aka febrile but bradycardic/normocardic = Legionella. Etc.

 

[nope80]

Also keep your eye out for buzz words, but know what the buzz words mean. The question will never say "red currant jelly sputum" (Klebsiella) but it will describe what red currant jelly would look like. Massive hemoptysis = Aspergillus. Temperature/Heart rate dissociation aka febrile but bradycardic = Legionella. Etc.

Exactly, thats what I have trouble with. Looking for "key" words or buzz words, but they are never there...ugh.

Any other non obvious associations to look for?

It really sucks when you think you have really studied something and find that you are getting all the questions wrong.👎thumbdown

 

[TMP-SMX]

Legionella. Outbreak in buildings and have diarrhea also.

Strep Pneumo usually rusty sputum but obviously catalase -, alpha hemolytic, optochin sensitive, G+ lancet shaped cocci seals it.

 

[alphaholic06]

Legionella. Outbreak in buildings and have diarrhea also.

Strep Pneumo usually rusty sputum but obviously catalase -, alpha hemolytic, optochin sensitive, G+ lancet shaped cocci seals it.

Legionella is also associated with hyponatremia.

 

[rahulb]

pertussis causes lymphocytosis and hits islets of langerhans causing hypoglycemia

 

[silas2642]

I need help with this one - are there any hints/clinical clues that people use to differentiate or particularly narrow in on the lung infections. I am literally getting every single on of these wrong and just can't seem to differentiate between all the viruses, bacterias, fungi, etc based on the questions in UWORLD. Does anyone have any clues or any thought process they go through to eliminate? I really really appreciate any help or advice. I need it 😳

I had a horrible time with the pneumonias too; I got a lot better when I memorized first aid micro section-- I've sort of forgotten a lot of it and need to go back and memorize it, but it really, really helped. I think I would try and pound FA in your head until you can't take it anymore and then see if that helps.

 

[Zweisamkeit]

Sorry if I'm hijacking the thread, but can someone please explain to me the differences among the clinical presentation and histology of asbestosis, silicosis, and berylliosis? I'm always getting these all confused. Thanks!

 

[ZagDoc]

Sorry if I'm hijacking the thread, but can someone please explain to me the differences among the clinical presentation and histology of asbestosis, silicosis, and berylliosis? I'm always getting these all confused. Thanks!

The clinical presentation for them all is very similar, as they all cause interstitial fibrosis. The differences are more epidemiological. The pneumoconioses questions that I've encountered pretty much always involve identifying the occupational risk factor and predicting outcome. It's basically mix and match job-to-syndrome, which means you need to know the jobs that the exposures are associated with.

Abestosis:
-Occupational hazard for shipyard workers, roofers, and demolition workers.
-Increased risk for bronchogenic carcinoma (risk increases synergistically with smoking), malignant mesothelioma. Benign pleural plaques (not pre-malignant) are almost always present.
-Ferringinous bodies characteristic.

Silicosis:
-Occupational hazard for metal foundary workers, miners. Most common of the pneumoconioses.
-Quartz is the instigating factor and causes extensive fibrosis.
-Hilar node calcifications.
-Increased risk for TB and lung cancer.

Coal Dust Pneumonconiosis:
-Occupational hazard for coal mines. Also seen due to smog.
-NO increased risk for cancer or TB.

Berylliosis:
-Aerospace and nuclear industry workers.
-Causes noncaseating granulomas within interstitial fibrosis.
-Increased risk for TB and lung cancer.

 

[nadk9f]

also for cryptococcus - pigeon poop; histoplasmosis - bat poop (aka cave explorer, but rmr that it has to be a more humid environment)

you should listen to goljan's lecture on this. it's golden.