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