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Upper Respiratory Tract InfectionsUpper Respiratory Tract Infections
Charles S. Bryan, M.D.November 20, 2007
Burden of URIBurden of URI
Up to ½ of all symptomatic illness
Significant morbidity and direct health care costs
Occasionally leads to fatal illness
Excessive use of antibiotics a major issue
The Common ColdThe Common Cold
Children average 8 per year, adults 3 Rhinoviruses 30 to 35%; coronaviruses about
10%, miscellaneous known viruses about 20%, presumed undiscovered viruses up to 35%, group A streptococci 5% to 10%
Sinusitis often present by CT scan; “rhinosinusitis” might be a better term
The common coldThe common cold
Transmission of rhinovirusesTransmission of rhinoviruses Direct contact is the most efficient means of
transmission: 40% to 90% recovery from hands.
Brief exposure (e.g., handshake) transmits in less than 10% of instances
Kissing does not seem to be a common mode of transmission.
Severe acute respiratory Severe acute respiratory distress syndrome (SARS)distress syndrome (SARS)
Caused by a previously unrecognized coronavirus—genome has now been sequenced.
Clinical manifestations are similar to those of other acute respiratory illnesses—notably, influenza
Cases in U.S.—associated mainly with travel or as secondary contacts
SARS: CDC case definition (2003)SARS: CDC case definition (2003)
Respiratory illness of unknown etiology AND Measured temperature > 100.4 degrees F (38
degrees C) AND One or more clinical findings of respiratory illness
AND Travel within 10 days of onset of symptoms to an
area with documented or suspected cases OR close contact with a case
SARS: Case definition (2)SARS: Case definition (2)
Clinical findings of respiratory illness: cough, SOB, dyspnea, hypoxia, or radiographic findings of either pneumonia or ARDS
Travel includes certain areas (mainland China, Hong Kong, Hanoi, Singapore) and also airports with documented or suspected community transmission
SARS: Radiographic findingsSARS: Radiographic findings Early: a peripheral/pleural-based
opacity (ground-glass or consolidative) may be the only abnormality. Look especially at retrocardiac area.
Advanced: widespread opacification (ground-glass or consolidative) tending to affect the lower zones and often bilateral.
Pleural effusions, lymphadenopathy, and cavitation are not seen.
SARS: Hypothetical disease modelSARS: Hypothetical disease model((Emerg Infect DisEmerg Infect Dis 2003; 9: 1064-1069) 2003; 9: 1064-1069)
Phase 1: viral replication Phase 2: immune hyperactivity with cytokine
deregulation (hence, the theoretical justification for corticosteroid therapy)
Phase 3: Pulmonary destruction
Dr. Carlo Urbani (1956-2003)Dr. Carlo Urbani (1956-2003) 2/28/03: Recognized
SARS while examining a patient in Hanoi.
Identified outbreak and raises the alarm.
Stayed caring patients despite multiple illnesses in staff—sent wife and three children back to Italy
3/29/03: Died of SARS
Acute bacterial sinusitisAcute bacterial sinusitis Viral infection--> obstruction of ducts and
compromise of mucocilary blanket--> acute infection from virulent organisms (most often S. pneumoniae and H. influenzae)--> opportunistic pathogens
Complicates 0.5% of common URI More common in adults than in children
Paranasal sinusesParanasal sinuses
Waters view (left); Coronal CTWaters view (left); Coronal CT
Acute sinusitis: complications Acute sinusitis: complications
Maxillary: usually uncomplicated Ethmoid: cavernous sinus thrombosis
(40% mortality) Frontal: osteomyelitis of frontal bone;
cavernous sinus thrombosis; epidural, subdural, or intracerebral abscess; orbital extension
Acute sinusitis: complications (2)Acute sinusitis: complications (2)
Sphenoid: Rare, but usually misdiagnosed, with grave consequences; extension to internal carotid artery, cavernous sinuses, pituitary, optic nerves; common misdiagnoses include ophthalmic migraine, aseptic meningitis, trigeminal neuralgia, cavernous sinus thrombosis
Chronic sinusitisChronic sinusitis
Bacterial: Cultures show a variety of opportunistic pathogens including anaerobes but problem is mainly anatomic, not microbiologic
Fungal: suspect especially when a single sinus is involved; syndromes associated with nasal polyposis can have high morbidity
Spectrum of fungal sinusitisSpectrum of fungal sinusitis
Simple colonization Sinus mycetoma (fungus
ball) Allergic fungal sinusitis Acute (fulminant) invasive
sinusitis (notably, rhinocerebral mucormycosis)
Chronic invasive fungal sinusitis
Otitis externaOtitis externa Acute, localized: often S. aureus or S.
pyogenes Acute diffuse (swimmer’s ear): gram-
negative rods, especially Ps. aeruginosa Chronic: mainly with chronic otitis media Malignant: life-threatening infection in
diabetics; Pseudomonas aeruginosa
Otitis externaOtitis externa Acute, localized: often S. aureus
or S. pyogenes Acute diffuse (swimmer’s ear):
gram-negative rods, especially Ps. aeruginosa
Chronic: mainly with chronic otitis media
Malignant: life-threatening infection in diabetics; Pseudomonas aeruginosa
Malignant otitis externaMalignant otitis externa
Diabetes mellitus Pseudomonas
aeruginosa Osteomyelitis of
the temporal bone Involvement of
vital structures at base of brain
Acute otitis mediaAcute otitis media
S. pneumoniae and H. influenzae the leading causes in all age groups
Moraxella catarrhalis: ? emerging role Some case may be viral Mycoplasma pneumoniae:
inflammation of the tympanic membrane (“bullous myringitis”)
Acute otitis mediaAcute otitis media
Critical role of eustachian tube as conduit between nasopharynx, middle ear, and mastoid air cells
Children have shorter, wider eustachian tubes than adults
Chronic otitis media and mastoiditisChronic otitis media and mastoiditis
Prolonged middle ear effusions in patients with previous episodes of acute otitis media. Often “skin flora” or anaerobic organisms
Mastoiditis: Less common nowadays. formerly severe complications. Often anaerobic.
Acute pharyngitis: physical examAcute pharyngitis: physical exam
Viral: edema and hyperemia of tonsils and pharyngeal mucosa
Streptococcal: exudate and hemorrhage involving tonsils and pharyngeal walls
Epstein-Barr virus (infectious mono): may also cause exudate, with nasopharyngeal lymphoid hyperplasia
Acute pharyngitis: physical exam (2)Acute pharyngitis: physical exam (2)
Adenoviruses: exudate may sometimes be present
Herpes simplex virus and some coxsackie A infections: vesiculation and mucosal ulceration may be present
Diphtheria: fibrous pseudomembrane with necrotic epithelium and leukocytes
Pharyngoconjuntival feverPharyngoconjuntival fever
Adenoviral pharyngitis Pharyngeal erythema and exudate may
mimic streptococcal pharyngitis Conjunctivitis (follicular) present in
1/3 to 1/2 of cases; commonly unilateral but bilateral in 1/4 of cases
HerpanginaHerpangina
Uncommon Due to coxsackieviruss Small, 1-2 mm vesicles on the soft
palate, uvula, and anterior tonsillar pillars which rupture to form small white ulcers
Occurs mainly in children
Vincent’s angina and QuinsyVincent’s angina and Quinsy
Vincent’s angina: anaerobic pharyngitis (exudate; foul odor to breath)
Quinsy: peritonsillitis/peritonsillar abscess. Medial displacement of the tonsil; often spread of infection to carotid sheath
DiphtheriaDiphtheria
Classic diphtheria (Corynebacterium diphtheriae): slow onset, then marked toxicity
Arcanobacterium hemolyticum (formerly Cornyebacterium hemolyticum): exudative pharyngitis in adolescents and young adults with diffuse, sometimes pruritic maculopapular rash on trunk and extremities
Miscellaneous causes of pharyngitisMiscellaneous causes of pharyngitis
Primary HIV infection Gonococcal infection Diphtheria Yersinia entercolitica (can have
fulminant course) Mycoplasma pneumoniae Chlamydia pneumoniae
Acute laryngotracheobronchitis (croup)Acute laryngotracheobronchitis (croup) Children, most often in 2nd year Parainfluenza virus type 1 most often in U.S.A. but
other agents cause Involvement of larynx and trachea: stridor,
hoarseness, cough Subglottic involvement: high-pitched vibratory
sounds Can lead to respiratory failure (up to 12%)
Acute epiglottitisAcute epiglottitis A life-threatening
cellulitis of the epiglottis and adjacent structures
Onset usually sudden (as opposed to gradual onset of croup); drooling, dysphagia, sore throat
H. influenzae the usual pathogen both in children (the usual patients) and adults
Acute suppurative Acute suppurative parotitisparotitis
Uncommon, but high morbidity and mortality
Usually associated some combination of dehydration, old age, malnutrition, and/or postoperative state
S. aureus the usual pathogen
Deep fascial space infections of Deep fascial space infections of the head and neckthe head and neck
Several syndromes according to anatomic planes
Can complicate odontogenic or oropharyngeal infection
Ludwig’s angina: bilateral involvement of submandibular and sublingual spaces (brawny cellulitis at floor of mouth)
Deep fascial space infections of Deep fascial space infections of the head and neck (2)the head and neck (2)
Lemierre syndrome: suppurative thrombophlebitis of internal jugular vein (Fusobacterium necrophorum)
Retropharyngeal space infection: contiguous spread from lateral pharyngeal space or infected retropharyngeal lymph node; complications include rupture into airway, septic thrombosis of internal jugular vein