Infections of Upper Respiratory Tract Flashcards
important upper respiratory tract infections
*pharyngitis
*tonsilitis
*epiglottitis
*laryngitis/subglottic airway including croup
*rhinitis/sinusitis
*bacterial sinusitis
*acute otitis media
host defense mechanisms of upper respiratory tract
*anatomic barriers
*normal colonizing microflora
*mucociliary barrier/clearance mechanisms
*secretory IgA
*cough/gag reflexes; sneeze mechanism
*glottic closure
general principles of URIs
*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
rhinitis/rhinosinusitis - overview & epidemiology
*“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
rhinitis/rhinosinusitis - incidence and outbreaks
*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
rhinitis/rhinosinusitis - transmission
*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)
rhinitis/rhinosinusitis - pathophysiology
- virus introduced into nose, oropharynx by inhalation, touching, or through lacrimal duct
- infects respiratory epithelium of vestibule, nasopharynx, possibly sinuses
- results in inflammation of mucosa and release of inflammatory mediators
- increased vessel permeability and congestion leading to the stuffy/runny nose
- infection can co-exist in oropharynx (pharyngitis) and lower large airways (acute bronchitis)
note - secondary viremia, if it occurs, is limited
rhinitis/rhinosinusitis - risk factors
*smoking
*behaviors (poor or no handwashing, masking, etc)
*humeral immunodeficiency
rhinitis/rhinosinusitis - viral pathogens
*rhinovirus
*coronavirus (non-covid) type 1-4
*COVID-19
*RSV
*parainfluenza virus types 1-4
rhinitis/rhinosinusitis - clinical presentation
*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
cold & COVID-19 vs. influenza
*fever, HA, myalgia, and malaise more consistent with influenza
*influenza has a more abrupt onset than colds
rhinitis/rhinosinusitis - diagnosis
*clinical
*rule out treatable conditions: influenza, COVID-19
*CXR if concerned about a lot of cough and possibility of mild pneumonia
rhinitis/rhinosinusitis - treatment
*NO ANTIBIOTICS
*decongestants, less so antihistamines
*if bronchospasm, tx with bronchodilators
rhinitis/rhinosinusitis - prevention
*avoid sick people
*wear a mask if in crowds during season or around close contacts
*handwashing/sanitize
acute bacterial sinusitis - pathophysiology
*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
acute bacterial sinusitis - etiology
*usually viral (rhinovirus, parainfluenza, and influenza)
*bacterial superinfection following viral infection
*sinus/nose drainage color means nothing
risk factors for bacterial superinfection (bacterial sinusitis)
*intranasal drug use
*problems with mucociliary clearance (CF, primary ciliary dyskinesia)
*immunodeficiency, especially IgA deficiency
*anatomic obstruction
*extension of dental infection into sinus space
how do you determine if “cold” is viral or bacterial superinfection (bacterial sinusitis)?
*double sickening (cold symptoms, start to feel better, then seems to come back worse)
*sinus pain, often unilateral
*tooth pain
*headache
*purulent drainage
bacterial sinusitis - most common pathogens
*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
bacterial sinusitis - treatment
- drainage
- antibiotic coverage (amoxicillin, amoxicillin/clavulanic acid, etc)
complications of sinusitis
*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)
pharyngitis - pathophysiology
*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
pharyngitis - etiologies
*VIRAL > bacterial (group A strep)
pharyngitis - clinical features
*sore throat, pain on swallowing
*exudates on tonsils/oropharynx
*suppurative vs. nonsuppurative
viral pharyngitis
*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
bacterial pharyngitis
*more common in children (30-60% of pharyngitis in kids is bacterial)
*predominantly caused by GROUP A STREPTOCOCCUS (strep. pyogenes → strep throat)
group A strep pharyngitis (strep throat)
*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
Streptococcus pyogenes (group A strep) - suppurative clinical infections
- pharyngitis
- Scarlet fever
complications of Group A Strep pharyngitis (strep pyogenes pharyngitis)
- scarlet fever:
-diffuse erythematous rash beginning on the chest and spreading to extremities
-complication of strep pharyngitis - Rheumatic fever:
-very rare now
-caused by M proteins and antigenic mimicry - parapharyngeal abscess
-possible complication of airway obstruction
-needs surgical drainage
bacterial pharyngitis - treatment
*penicillin for 10 days
*cephalosporin or macrolides are effective if allergic
*drainage for peritonsillar abscess
“Ludwig’s angina”
*bilateral infection of the floor of the mouth
*aggressive, rapidly spreading “woody” cellulitis
*febrile, mouth pain, stiff neck, drooling, dysphagia
epiglottitis - pathophysiology
*rapidly progressive cellulitis of the epiglottis and surrounding tissues
epiglottitis - etiology
*pediatric age group: H. flu type B (rare now due to HIB vaccine)
*adults: nontypable H. flu, strep pneumo, staph aureus
epiglottitis - symptoms
*dysphagia, odynophagia, fever, stridor, inability to manage secretions (drooling), hot potato voice
epiglottitis - treatment
*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)
laryngitis - pathophysiology
*viral infection predominately about the larynx
laryngitis - etiology
viral, similar to those due to nasopharyngitis
laryngitis - symptoms
*hoarseness, acute
*sore throat
*sometimes URI symptoms
*usually lack of fever and systemic symptoms
*self-limited, symptomatic treatment, no antibiotics
subglottic infection (croup)
*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
otitis media - pathophysiology
*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
otitis media - common causes
*following viral URIs most common
*bacterial pathogens: strep pneumo, H. flu, moraxella, mycoplasma
otitis media - symptoms
*fussiness
*fever
*tugging on ear
*double sickening
*hearing difficulty
*exam:
-TM erythema
-bulging
-decreased compliance on pneumatoscopy of tympanogram
otitis media - complications
*TM perforation
*decreased auditory acuity and auditory development
*mastoiditis
*temporal bone infection
*meningitis
*BULLOUS MYRINGITIS = mycoplasma pneumonia infection
otitis media - treatment
*Amoxicillin or Amoxicillin-Clavulanate for 4-7 days
*alternative 2nd generation cephalosporin or macrolide (clarithromycin or azithromycin)
bullous myringitis seen on examination of ears is pathognomonic for what infection?
BULLOUS MYRINGITIS = mycoplasma pneumonia infection
