Typical vs atypical. CAP vs HAP. The organisms, the x-rays, the board traps. Every vignette starts with a cough.
A 72-year-old nursing home resident develops fever, productive cough with rusty sputum, and rigors. CXR shows lobar consolidation. Which organism?
Every pneumonia vignette is asking you one question first: typical or atypical? Get this right and you're halfway to the answer.
🔑 Memory hook Typical is LOUD · high fever, productive cough, one lobe lights up. Atypical is QUIET · low fever, dry cough, hazy everywhere. Loud bugs are bacterial bullies. Quiet bugs sneak in.
Each organism has a signature vignette. clinical medicine test the signature, not the exception.
🔑 Memory hook Rusty = Pneumo (old blood, classic). Currant jelly = Klebsiella (thick, sweet, destructive). Walking = Myco (patient walks in, x-ray says they shouldn't). GI + water = Legio (cruise ship diarrhea that went to the lungs).
😈 Pathogen Villain Cards
Tap each card. The board signature is on the back.
Tap to flip
Drag each clinical finding to the correct organism. Wrong answers bounce back.
Treatment depends on ONE question: outpatient, inpatient floor, or ICU?
Amoxicillin (typical coverage) OR
Doxycycline (covers typical + atypical) OR
Macrolide (azithromycin) · only if local resistance < 25%
Why not azithromycin first? Resistance. clinical medicine will test this.
Comorbidities = broader coverage needed
Respiratory fluoroquinolone (levofloxacin, moxifloxacin) OR
Amoxicillin-clavulanate + macrolide
The fluoroquinolone covers both typical AND atypical in one pill. That's why it's preferred for comorbid patients.
Respiratory fluoroquinolone alone OR
Beta-lactam + macrolide (ceftriaxone + azithromycin)
The ceftriaxone + azithromycin combo is the most tested combination in clinical practice. Ceftriaxone for typical organisms, azithromycin for atypical coverage.
Beta-lactam + macrolide (minimum) OR
Beta-lactam + respiratory fluoroquinolone
If Pseudomonas risk: anti-pseudomonal beta-lactam (piperacillin-tazobactam, cefepime, or meropenem) + fluoroquinolone
If MRSA risk: add vancomycin or linezolid
ICU = never monotherapy. Board trap: student picks levofloxacin alone for ICU patient. Wrong.
🔑 Memory hook Outpatient healthy = simple (amoxicillin). Outpatient sick = fancy (fluoroquinolone). Inpatient = combo meal (ceftriaxone + azithro). ICU = everything on the menu. Escalation ladder: sicker patient = more drugs.
Trap #1: "Got better then got worse"
Patient had influenza, improved, then rapidly deteriorated with high fever and bilateral infiltrates. This is post-influenza S. aureus pneumonia. The "biphasic illness" is the giveaway.
Trap #2: Alcoholic with pneumonia
If the sputum is currant jelly and there's upper lobe cavitation = Klebsiella. But the #1 cause of pneumonia in alcoholics is still S. pneumoniae. clinical medicine test both · read the sputum description.
Trap #3: Ventilator pneumonia timing
Early VAP (< 5 days) = normal bugs (S. pneumo, H. flu, MSSA). Treat narrow.
Late VAP (> 5 days) = MDR bugs (Pseudomonas, Acinetobacter, MRSA). Treat wide.
Trap #4: Pneumonia + diarrhea
If the vignette mentions GI symptoms alongside pneumonia · especially with a water source (hotel, cruise, AC unit) and hyponatremia · it's Legionella. Not just an atypical pneumonia. THE atypical pneumonia with GI involvement.
Trap #5: Cystic fibrosis pneumonia
First infection in CF kids: S. aureus. Chronic colonizer in CF adults: Pseudomonas. They will give you a CF patient's age to see if you know which one to pick.
Trap #6: PCP prophylaxis threshold
CD4 < 200 = start TMP-SMX prophylaxis. The patient doesn't have PCP yet · the question is asking when to start prevention. If PaO2 < 70 during active PCP, add steroids.
Clinical clues appear one at a time. After each clue, tap the organism you think it is. Fewer clues = better instinct.
ALGORITHM
Setting and patient first. Every branch ends with a diagnosis and a drug.
Original clinical vignettes. Shuffled, never-repeat, full explanations for every choice.