Infections of Upper Respiratory Tract

Question 1

important upper respiratory tract infections

Answer 1

*pharyngitis
*tonsilitis
*epiglottitis
*laryngitis/subglottic airway including croup
*rhinitis/sinusitis
*bacterial sinusitis
*acute otitis media

Question 2

host defense mechanisms of upper respiratory tract

Answer 2

*anatomic barriers
*normal colonizing microflora
*mucociliary barrier/clearance mechanisms
*secretory IgA
*cough/gag reflexes; sneeze mechanism
*glottic closure

Question 3

general principles of URIs

Answer 3

*represent MOST COMMON ILLNESSES of humans
*usually minor (but can result in lost productivity and social opportunities)
*usually self-limiting even without treatment
*mostly viral in etiology, but bacteria and some fungi/mycobacteria also contribute
*primarily designated based on bases of predominant site of anatomic and symptomatic involvement
*Rx of these disorders represents most frequent misuse of antibiotics
*goal of evaluation is to identify TREATABLE syndromes/prevent complications

Question 4

rhinitis/rhinosinusitis - overview & epidemiology

Answer 4

*“the common cold”
*VIRAL infection
*major cause of health care dollar and provider utilization annually
*benign, self limited syndrome
*average episodes per year:
-5-7/year for preschool age children
-2-3/year by adulthood

Question 5

rhinitis/rhinosinusitis - incidence and outbreaks

Answer 5

*incidence increased in late fall, winter, and early spring:
-decreased temp and humidity which increases viral longevity in the environment
-closer human to human contact
-holiday get-togethers
*geographic outbreaks
*local community epidemiology (school, work, etc)
*congregate settings at higher risk of outbreaks
*family outbreaks
*age affects specific viruses and clinical presentation

Question 6

rhinitis/rhinosinusitis - transmission

Answer 6

*respiratory droplets
*aerosols transmission over distance can occur but not as important
*can occur by direct contact (handshake) or from a fomite (not as important)

Question 7

rhinitis/rhinosinusitis - pathophysiology

Answer 7

1. virus introduced into nose, oropharynx by inhalation, touching, or through lacrimal duct
2. infects respiratory epithelium of vestibule, nasopharynx, possibly sinuses
3. results in inflammation of mucosa and release of inflammatory mediators
4. increased vessel permeability and congestion leading to the stuffy/runny nose
5. infection can co-exist in oropharynx (pharyngitis) and lower large airways (acute bronchitis)

note - secondary viremia, if it occurs, is limited

Question 8

rhinitis/rhinosinusitis - risk factors

Answer 8

*smoking
*behaviors (poor or no handwashing, masking, etc)
*humeral immunodeficiency

Question 9

rhinitis/rhinosinusitis - viral pathogens

Answer 9

*rhinovirus
*coronavirus (non-covid) type 1-4
*COVID-19
*RSV
*parainfluenza virus types 1-4

Question 10

rhinitis/rhinosinusitis - clinical presentation

Answer 10

*incubation period 24-72 hours
*rhinitis, nasal congestion/obstruction, sneezing (days 1-3)
*if fever, usually on day 1 and limited
*sore throat early
*if airway involvement, cough develops day 4-5, with decreasing nasal symptoms
*duration averages 5-7 days, but can extend to 2 weeks
*for patients at the extremes of age or who are immunocompromised can uncommonly be complicated by viral pneumonia

Question 11

cold & COVID-19 vs. influenza

Answer 11

*fever, HA, myalgia, and malaise more consistent with influenza
*influenza has a more abrupt onset than colds

Question 12

rhinitis/rhinosinusitis - diagnosis

Answer 12

*clinical
*rule out treatable conditions: influenza, COVID-19
*CXR if concerned about a lot of cough and possibility of mild pneumonia

Question 13

rhinitis/rhinosinusitis - treatment

Answer 13

*NO ANTIBIOTICS
*decongestants, less so antihistamines
*if bronchospasm, tx with bronchodilators

Question 14

rhinitis/rhinosinusitis - prevention

Answer 14

*avoid sick people
*wear a mask if in crowds during season or around close contacts
*handwashing/sanitize

Question 15

acute bacterial sinusitis - pathophysiology

Answer 15

*secondary to obstruction of sinus ostium and lack of drainage
*hypo-oxygenation of sinus
*impaired ciliary and mucosal function, leading to bacterial overgrowth
*difficult to distinguish from protracted but uncomplicated cold

Question 16

acute bacterial sinusitis - etiology

Answer 16

*usually viral (rhinovirus, parainfluenza, and influenza)
*bacterial superinfection following viral infection
*sinus/nose drainage color means nothing

Question 17

risk factors for bacterial superinfection (bacterial sinusitis)

Answer 17

*intranasal drug use
*problems with mucociliary clearance (CF, primary ciliary dyskinesia)
*immunodeficiency, especially IgA deficiency
*anatomic obstruction
*extension of dental infection into sinus space

Question 18

how do you determine if “cold” is viral or bacterial superinfection (bacterial sinusitis)?

Answer 18

*double sickening (cold symptoms, start to feel better, then seems to come back worse)
*sinus pain, often unilateral
*tooth pain
*headache
*purulent drainage

Question 19

bacterial sinusitis - most common pathogens

Answer 19

*community acquired organisms: Strep pneumonia, H. influenza, Moraxella, Mycoplasma

*hospital acquired sinusitis: uncommon, but includes staph aureus, pseudomonas, candida albicans, fungal etiologies in immunocompromised patients

Question 20

bacterial sinusitis - treatment

Answer 20

1. drainage
2. antibiotic coverage (amoxicillin, amoxicillin/clavulanic acid, etc)

Question 21

complications of sinusitis

Answer 21

*overall, very rare; sphenoidal and frontal sinus infection should be referred

*orbital cellulitis (due to ethmoidal sinus infection)
*frontal or temporal lobe abscess
*cavernous sinus thrombosis (usually sphenoidal sinusitis)
*Pott’s puffy tumor (frontal bone osteomyelitis from frontal sinus infection)

Question 22

pharyngitis - pathophysiology

Answer 22

*inflammation of mucosal surfaces of the pharynx
*often with inflammation of palatine tonsils
*may occur in isolation or associated with constellation of symptoms in upper respiratory infections

Question 23

pharyngitis - etiologies

Answer 23

*VIRAL > bacterial (group A strep)

Question 24

pharyngitis - clinical features

Answer 24

*sore throat, pain on swallowing
*exudates on tonsils/oropharynx
*suppurative vs. nonsuppurative

Question 25

viral pharyngitis

Answer 25

*80-90% of pharyngitis in adults
*usually in association with rhinosinusitis and viral bronchitis
*same viruses as rhinosinusitis
*adenovirus seen sometimes in outbreaks in congregate communities or collage dorms

Question 26

bacterial pharyngitis

Answer 26

*more common in children (30-60% of pharyngitis in kids is bacterial)
*predominantly caused by GROUP A STREPTOCOCCUS (strep throat)

Question 27

group A strep pharyngitis (strep throat)

Answer 27

*more common in children
*Centor Criteria for GAS pharyngitis:
1. fever
2. exudate pharyngitis
3. tender anterior cervical adenonitis
4. absence of cough
*RAPID STREP TEST with confirmatory culture in children:
-80-85% sensitive, > 90% specificity
-potential long-term consequences if not treated

Question 28

Streptococcus pyogenes (group A strep) - suppurative clinical infections

Answer 28

1. pharyngitis
2. Scarlet fever

Question 29

complications of Group A Strep pharyngitis (strep pyogenes pharyngitis)

Answer 29

1. scarlet fever:
   -diffuse erythematous rash beginning on the chest and spreading to extremities
   -complication of strep pharyngitis
2. Rheumatic fever:
   -very rare now
   -caused by M proteins and antigenic mimicry
3. parapharyngeal abscess
   -possible complication of airway obstruction
   -needs surgical drainage

Question 30

bacterial pharyngitis - treatment

Answer 30

*penicillin for 10 days
*cephalosporin or macrolides are effective if allergic
*drainage for peritonsillar abscess

Question 31

“Ludwig’s angina”

Answer 31

*bilateral infection of the floor of the mouth
*aggressive, rapidly spreading “woody” cellulitis
*febrile, mouth pain, stiff neck, drooling, dysphagia

Question 32

epiglottitis - pathophysiology

Answer 32

*rapidly progressive cellulitis of the epiglottis and surrounding tissues

Question 33

epiglottitis - etiology

Answer 33

*pediatric age group: H. flu type B (rare now due to HIB vaccine)
*adults: nontypable H. flu, strep pneumo, staph aureus

Question 34

epiglottitis - symptoms

Answer 34

*dysphagia, odynophagia, fever, stridor, inability to manage secretions (drooling), hot potato voice

Question 35

epiglottitis - treatment

Answer 35

*emergency!
*DO NOT attempt to visualize oropharynx or extend neck
*EARLY intubation by anesthesia, preferably in OR (high risk of losing airway and requiring emergency alternative airway placement)
*antibiotics (cefotaxime, ceftriaxone, cefuroxime, etc)
*decadron (steroid)

Question 36

laryngitis - pathophysiology

Answer 36

*viral infection predominately about the larynx

Question 37

laryngitis - etiology

Answer 37

viral, similar to those due to nasopharyngitis

Question 38

laryngitis - symptoms

Answer 38

*hoarseness, acute
*sore throat
*sometimes URI symptoms
*usually lack of fever and systemic symptoms
*self-limited, symptomatic treatment, no antibiotics

Question 39

subglottic infection (croup)

Answer 39

*viral infection predominantly about the larynx, post-glottal airways
*caused by the same viruses that cause nasopharyngitis
*commonly seen in fall and early winter
*primary symptom = BARKING COUGH (sounds like a seal) that commonly happen at night
*anatomic hallmark of croup is narrowing of subglottic airway

Question 40

otitis media - pathophysiology

Answer 40

*infection of the middle ear
*most common in children under the age of 5
*often a complication of rhinosinusitis due to ET obstruction and poor drainage (often follows viral URIs)
*related to underdevelopment of eustachian tube

Question 41

otitis media - common causes

Answer 41

*following viral URIs most common
*bacterial pathogens: strep pneumo, H. flu, moraxella, mycoplasma

Question 42

otitis media - symptoms

Answer 42

*fussiness
*fever
*tugging on ear
*double sickening
*hearing difficulty
*exam:
-TM erythema
-bulging
-decreased compliance on pneumatoscopy of tympanogram

Question 43

otitis media - complications

Answer 43

*TM perforation
*decreased auditory acuity and auditory development
*mastoiditis
*temporal bone infection
*meningitis
*BULLOUS MYRINGITIS = mycoplasma pneumonia infection

Question 44

otitis media - treatment

Answer 44

*Amoxicillin or Amoxicillin-Clavulanate for 4-7 days
*alternative 2nd generation cephalosporin or macrolide (clarithromycin or azithromycin)

Question 45

bullous myringitis seen on examination of ears is pathognomonic for what infection?

Answer 45

BULLOUS MYRINGITIS = mycoplasma pneumonia infection