30. H+N Microbio

Question 1

Causes of URIs

Answer 1

VIRAL - rhinovirus, coronavirus, parainfluenza, RSV, influenza, adenovirus, human metapneumovirus, COVID

Question 2

Common causes of pharyngitis

Answer 2

1: Group A Strep (s. pyogenes) - 20-30% peds pharyngitis, 5-15% adult pharyngitis, sudden onset of sore throat, fever (no cough/rhinorrhea), pharyngeal/tonsillar edema, white tonsillar exudates, palatal petechiae, lymphadenopathy (scalet fever - red papular rash), Tx: PENICILLIN to prevent scary complications (PSGN, rheumatic fever)

tests: reactive lymphocytes on blood smear, heterophile antibody test
Tx: supportive (no good tx), may get rash if take amoxicillin, no contact sports (splenomegaly)

Other: Arcanobacterium haemolyticum, HSV, N. gonorrhoeae, Candida (thrush)

Question 3

Common cause of oral cavity infections

Answer 3

HSV Gingivostomatitis - inflammation of oral mucosa and gingiva, primary HSV infection (fever, malaise, headache), numerous vesicles progress to ulcers, recurrent cold sores

Other causes: Herpangina (Coxsackie A virus - ulcers to soft palate, anterior pillars only), Hand foot and mouth disease (Coxsackivirus/enterovirus - vesicles/blisters on mouth)

Question 4

Causes of Epiglottitis

Answer 4

1: H flu type b - now decreased due to Hib vaccine

Now, S. pneumo, S. pyogenes, S. aureus
CP: fever, throat pain, dysphagia, drooling, hoarseness, stridor
XRay: thumbprint sign
tx: ABx

Question 5

Lemierre Syndrome

What is it, what bacteria causes it, tx

Answer 5

complication of bacterial pharyngitis/tonsillitis - infection spreads into lateral pharyngeal spaces of neck - septic thrombophlebitis of internal jugular vein (cause pulmonary embolism)

due to Fusobacterium necrophorum
JV thrombosis
Tx: ABx (assume PCN resistant)

Question 6

Ludwig Angina

what is it, what causes it, complications, CP, tx

Answer 6

life-threatening cellulitis of soft tissue in floor of mouth/neck
Infection of many normal mouth flora: staph, strep, fusobacterium, bacteriodes, actinomyces

Complications: aspiration pneumonia, mediastinitis, airway compromise
CP: BULL NECK
TX: widespread ABx coverage (multiple bugs involveD)

Question 7

Most common causes of AOM

Answer 7

1. Viral
2. S. Pneumo, H. Flu, M. catarrhalis
   spreads from eustachian tube

Question 8

Most common causes of Otitis Externa, tx

Answer 8

1. Pseudomonas aeruginosa
2. S. aureus

SWIMMERS EAR
Tx: topical abx

Question 9

Most common causes of sinusitis

Answer 9

1. VIRUSES

2. S. pneumo > H. flu > M. catarrhalis

Question 10

How to distinguish preseptal cellulitis from orbital cellulitis

Answer 10

look for absence of orbital involvement

Question 11

Cercivofacial actinomycosis: what is it, cp

Answer 11

Actinomyces infection, complicating teeth/gum infection = LUMPY JAW