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Upper Respiratory Tract InfectionsUpper Respiratory Tract Infections
Divya Ahuja, M.D.November 2009
Burden of URIBurden of URI
Significant morbidity and direct health care costs
Direct costs of $ 17 billion annually
Occasionally leads to fatal illness
Excessive use of antibiotics a major issue
The Common ColdThe Common Cold
Children average 8 per year, adults 3 Etiologies :
– Rhinoviruses 30 to 35%– Coronaviruses about 10%– Miscellaneous known viruses about 20%– Influenza and adenovirus-30%– Presumed undiscovered viruses up to 35%– Group A streptococci 5% to 10%
Parainfluenza was the first respiratory virus isolated (1955) Seasonal variation
– Rhinovirus early fall– Coronavirus- winter
Common ColdCommon Cold
Common symptoms are sore throat, runny nose, nasal congestion, sneezing,
Sometimes accompanied by conjunctivitis, myalgias, fatigue
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.
Infectious droplet nuclei Brief exposure (e.g., handshake) transmits in
less than 10% of instances Kissing does not seem to be a common mode
of transmission.
Clinical characteristicsClinical characteristics
Incubation period 12-72 hours Nasal obstruction, drainage, sneezing,
scratchy throat Median duration 1 week but 25% can last 2
weeks Pharyngeal erythema is commoner with
adenovirus than with rhino or coronavirus
Diagnosis and treatmentDiagnosis and treatment
Main challenge is to distinguish between uncomplicated cold and streptococcal pharyngitis or bacterial sinusitis– Good examination
Marked exudate or pharyngeal erythema suggests– Streptococcal infection– Adenovirus– Diphtheria
Rapid antigen tests for group A streptococcus Rapid techniques for influenza, RSV, parainfluenza Treat with NSAIDs and whatever else your grandmother
advises
Acute bacterial sinusitisAcute bacterial sinusitis Epidemiological studies suggest 1 billion cases of viral
rhinosinusitis occur annually in the US Of these0.5-2% are complicated by 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
Nose blowing generates high intranasal pressures that deposit bacteria into the sinus cavity
More common in adults than in children
Paranasal sinusesParanasal sinuses
Waters view (left); Coronal CTWaters view (left); Coronal CT
SinusitisSinusitis Community acquired bacterial sinusitis
– S.pneumoniae– H. influenzae– S. pyogenes
Nosocomial sinusitis– Seen in critically ill, mechanically ventilated
S. aureus Pseudomonas aeruginosa Serratia marcescens
– fungal
Clinical featuresClinical features
Clinical features– Sneezing– Nasal discharge– Facial pressure– Fever– Purulent drainage– Headache
Sinus imaging not routinely recommended
Acute sinusitis: complications Acute sinusitis: complications
Maxillary: usually uncomplicated Ethmoid: cavernous sinus thrombosis-serious Frontal: osteomyelitis of frontal bone; cavernous
sinus thrombosis; epidural, subdural, or intracerebral abscess; orbital extension
Sphenoid: Rare; extension to internal carotid artery, cavernous sinuses, pituitary, optic nerves; common misdiagnoses include ophthalmic migraine, aseptic meningitis, trigeminal neuralgia, cavernous sinus thrombosis
Case Case
BR 59 year old white female Diplopia and left temporal headache Thought to have temporal arteritis Started on Prednisone 100mg once daily Two months later developed cranial N palsies,
headaches
Chronic sinusitisChronic sinusitis
The previous patient had an invasive aspergillus sinusitis as a result of chronic high dose steroid therapy, resulting in occlusion of carotid artery and invasion into the brain. She died in a month.
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;
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, S.
epidermidis or S. pyogenes Acute diffuse (swimmer’s ear): gram-
negative rods, especially Ps. Aeruginosa ; Rx: topical quinolones
Chronic: mainly with chronic otitis media
Malignant: life-threatening infection in diabetics, elderly, immunecompromised
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 (most H. flu is from non-typable strains and not “B”)
Moraxella catarrhalis: 10% of cases Some cases may be viral (RSV, influenza,
enteroviruses) 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
Diagnosis and treatmentDiagnosis and treatment
Presence of fluid in the middle ear AND Ear pain, drainage, hearing loss The fluid may take weeks to resolve Amoxicillin remains the drug of choice Beta-lactamase producing strains of H.
influenza will need amoxicillin/clavulanic acid or cephalosporins
Otitis Media
Acute pharyngitisAcute pharyngitis
Inflammatory syndrome of the pharynx– Most cases are viral– Most important bacterial cause is
Streptococcus pyogenes (15-20%) Presents with sore or scratchy throat In severe bacterial cases there may be
odynophagia, fever, headache
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
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
Vesicular lesionsVesicular lesions
Herpangina – 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 Also think of Herpes simplex virus when you see
vesicular lesions
Vincent’s angina and QuinsyVincent’s angina and Quinsy
Vincent’s angina: anaerobic pharyngitis (exudate; foul odor to breath)
Ludwig’s angina- cellulitis of dental origin Quinsy: peritonsillitis/peritonsillar abscess.
Medial displacement of the tonsil; often spread of infection to carotid sheath
Diphtheriafibrous pseudomembrane with necrotic epithelium and leukocytes
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
TreatmentTreatment
Symptomatic Penicillin for Strep throat Macrolides for pen allergic patients Add an anti-anaerobic agent for Vincent’s
and Ludwig’s angina
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 are Mycoplasma pneumoniae, H. influenza Involvement of larynx and trachea: stridor, hoarseness,
cough Subglottic involvement: high-pitched vibratory sounds Can lead to respiratory failure (2% get hospitalized)
CroupCroup
Rhinorrhea, sore throat, mild cough, fever Parainfluenzae and influenza can be
identified by nasopharyngeal swab Rapid tests are available Treat with vaporizers, nebulized adrenaline Systemic or nebulized corticosteroids in the
severely sick
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 with 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
Lemierre’s syndrome
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: 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.
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
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