1. MRSA vs MSSA vs Strep by eye: 
-Classic story for MRSA-- very fast onset, very painful abscess
-Erysipelas: very superficial infection heaped up edges, razor sharp borders. more likely strep
-Cellulitis: has fuzzier edges, red, usually MSSA and strep.
-Boils: usually staph, I&D, probably don't need abx but if you're gonna give something, bactrim/clinda.
-If its a MRSA picture, vanc if theyre admited, bactrim if they're not.
2. Amino penicillins - good for head and neck infections (covers triad of s.pneumo, h.flu, moraxella that's so common in acute otitis media, sinusitis, etc)
3. Clindamycin - inhibits protein synthesis, good as initial treatment for toxin-based staph infections (SSSS, toxic shock) to decrease toxin production before bactericidal agents.
4. Tetracyclines-- pill esophagitis, need to take with a lot of water. Can also cause drug-induced lupus (minocycline is the worst).
5. Carbapenems are first line in necrotizing pancreatitis.
6. Headache, stiff neck, AMS: 
-Meningitis
-Neisseria > S.pneumo
-Ceftriaxone (covers neisseria and s.pneumo), add vanc b/c 20% ceftriaxone resistance in s.pneumo (worse in texas). Vanc doesn't usually cross BBB but in meningitis the BBB is shot anyways.
7. Headache, fever, confusion. 
- Encephalitis
-usually HSV, VZV, TB, arboviruses (west nile etc), lyme disease.
-Treat with empiric acyclovir and consider adding doxy to cover lyme and ceftriaxone to cover for bacterial meningitis just in case.
8. Headache, focal neuro deficits - 
-Brain abscess
-Common in IV drug users
-usually staph, but also bacteroides, e.coli, and weird stuff (TB, syphillis)
-Cover everything. Ceftriaxone + flagyl, add vanc if you suspect staph
9. Fever, facial pain, nasal discharge
-Sinusitis.
-Usually viral. After that, s.pneumo, h.flu, moraxella
-Signs that its bacterial: headache leaning forward, maxillary tooth pain,
-Empirically start on amox or bactrim, go to augmentin if you suspect resistance.
-Also aggressively decongest with sudafed, afrin, nettipot.
10. Sore throat, fever, exudate
-Usually streph pharyngitis, but can be EBV (consider if they don't get better on antibiotics).
-Empirically treat with penicillin.
-Watch out: If you treat with something other than penicillin, like azithro, it doesn't cover fusibacterium, and they might end up with Lemieres disease.
-Other complications: neck, retropharyngeal abscesses