L24 Upper Respiratory Tract Infections Flashcards
___________________ are the most common acute illness seen in outpatient care. They are typically _____________
Upper respiratory tract infections are the most common cute illness seen in outpatient care. They are typically VIRAL
Acute Pharyngitis
TRIAD of symptoms?
Causative Pathogens?
Demographics?
Acute Pharyngitis
TRIAD: Sore Throat, Fever, Pharyngeal Inflammation (Characterized by Erthymea and edema)
Cuases:
Typically viral and self limiting (25% to 45% of cases)– rhinovirus** and **coronavirus most common
Most common bacterial cause is S. pyogenes (Group A Strep)
5-18 y/o is the greatest prevalence of cases
Acute Pharyngitis
TRIAD of symptoms?
Causative Pathogens?
Demographics?
Acute Pharyngitis
TRIAD: Sore Throat, Fever, Pharyngeal Inflammation (Characterized by Erthymea and edema)
Cuases:
Typically viral and self limiting (25% to 45% of cases)– rhinovirus** and **coronavirus most common
Most common bacterial cause is S. pyogenes (Group A Strep)
5-18 y/o is the greatest prevalence of cases
Differentiating Viral and Bacterial Causes of Pharyngitis?
Viral Cause
Mild pharyngeal symptoms with:
Rhinorrhea (runny nose)
Cough
Conjunctivitis
oral ulcers (HSV, coxsackievirus)
Streptococcus pyogenes (GAS): most common and important bacterial cause of Acute Pharyngitis
History: sudden onset with temperature >38.3°C, marked pharyngeal pain and odynophagia
Signs:
intense pharyngeal erythema
enlarged tonsils
grey-white exudate covering posterior pharynx and tonsillar pillars
pronounced oedema of uvula
petechiae sometimes seen on soft palate (Pinpoint Hemorrhaging)
tender anterior cervical lymphadenopathy
_____________________
- 0.5-2.5% of bacterial pharyngitis
- highest frequency in adolescents and young adults
- exudative pharyngitis, clinically similar to GAS pharyngitis
- generalized maculopapular rash – most prominent on extremities
Arcanobacterium haemolyticum
- 0.5-2.5% of bacterial pharyngitis
- highest frequency in adolescents and young adults
- exudative pharyngitis, clinically similar to GAS pharyngitis
- generalized maculopapular rash – most prominent on extremities
________________
• mild pharyngeal discomfort characterized as soreness, scratchiness or irritation
• pharynx appear normal or mild oedema and erythema
- Sneezing, nasal discharge/congestion) precede throat symptoms
- non-productive cough usually present
NOT SEEN?
Common Cold
• mild pharyngeal discomfort characterized as soreness, scratchiness or irritation
• pharynx appear normal or mild oedema and erythema
- Sneezing, nasal discharge/congestion) precede throat symptoms
- non-productive cough usually present
NOT SEEN:
systemic complaints (fever, chills, myalgia)
exudates and painful lymphadenopathy
_________________:
- 25% of cases of Acute Pharyngitis in children and 3% of adults
- thick and white exudates
- What can it progress to?
Adenovirus
- 25% of cases in children and 3% of adults
- thick and white exudates
• Pharyngoconjunctival Fever
– outbreaks and history of swimming pool exposure
– conjunctivitis, pharyngitis, lymphadenopathy and systemic features (myalgia, chills)
– highly contagious
Epstein-Barr virus (EBV)
- infectious mononucleosis defined by triad of ___________, _____________,________________
- adolescents and young adults
- pharyngitis subacute in onset with moderate to marked:
enlargement of tonsils
exudates
palatal petechiae
• painful anterior and posterior cervical lymphadenopathy
What happens when given ampicillin?
Epstein-Barr virus (EBV)
- infectious mononucleosis defined by triad of fever, pharyngitis and adenopathy
- adolescents and young adults
- pharyngitis subacute in onset with moderate to marked:
enlargement of tonsils
exudates
palatal petechiae
- painful anterior and posterior cervical lymphadenopathy
- diffuse pruritic maculopapular eruption in patients given ampicillin
Herpangina
- majority of cases due to _____________
- primarily in ________
- severe _______ illness with marked sore throat and dysphagia
- pharyngeal erythema with discrete multiple vesicles on soft palate, uvula, and anterior tonsillar pillars which rupture to form _____________
Herpangina
- majority of cases due to group A coxsackieviruses
- primarily in children
severe febrile illness with marked sore throat and dysphagia
• pharyngeal erythema with discrete multiple vesicles on soft palate, uvula, and anterior tonsillar pillars which rupture to form small shallow ulcers
Hand-foot-and-mouth Disease
- due to ___________________
- characterized by __________________ and ____________ in pharynx
- vesicles also noted on hands, feet and buttock
Hand-foot-and-mouth Disease
- due to group A coxsackieviruses
- characterized by erythematous-based vesicles and ulcerations in pharynx
- vesicles also noted on hands, feet and buttock
Herpes simplex virus
• primary infection causes
– ___________ in young children
– ___________ in adolescents and young adults
- fever, pharyngeal erythema, exudates and tender cervical adenopathy
- vesicles and shallow ulcers of mouth, lips or pharynx
Herpes simplex virus
• primary infection causes
– gingivostomatitis in young children
– pharyngitis in adolescents and young adults
- fever, pharyngeal erythema, exudates and tender cervical adenopathy
- vesicles and shallow ulcers of mouth, lips or pharynx
Complications of Pharyngitis?
Suppurative (Pus) Complications:
Peritonsillar abscess (quinsy)
- typically adolescents and young adults
- fever, malaise, severe sore throat, odynophagia, drooling and a muffled voice (“hot potato voice”)
- swelling of anterior tonsillar pillar and soft palate
- uvula displaced to contralateral side
- tender cervical adenopathy
Treatment:drainage of purulent material coupled with antibiotics
Retropharyngeal abscess
Sinusitis
otitis media
Mastoiditis
invasive infections (necrotizing fasciitis and toxic shock syndrome with GAS).
Nonsuppurative complications of GAS:
acute rheumatic fever
acute glomerulonephritis
viral pharyngitis may be complicated by a secondary bacterial infection (sinusitis, pneumonia)
Pharyngitis Investigation/Management?
Investigation
Rapid antigen detection test (RADT): test for Streptococcus pyogenes (GAS) if cannot rule out on clinical grounds
– positive result is diagnostic
– perform throat culture in children and adolescents with negative test
– timely treatment and reduce over-treatment of viral causes
Management
10-day course of oral penicillin V** or **amoxicillin
Macrolide or cephalosporin for penicillin-allergic patients
_____________ an acute illness marked by middle ear inflammation that results in middle ear fluid collection and associated local and systemic features.
______________ is middle ear effusion in the absence of acute infection.
______________ is a condition with persistent drainage and perforation lasting longer than 6 weeks
acute otitis media (AOM) an acute illness marked by middle ear inflammation that results in middle ear fluid collection and associated local and systemic features.
otitis media with effusion (OME) is middle ear effusion in the absence of acute infection.
chronic suppurative otitis media (CSOM) is a condition with persistent drainage and perforation lasting longer than 6 weeks
Epidemiology/Risk Factors of Otitis Media
Epidemiology
90% of children have at least one episode by 2 years of age.
highest incidence between 6 and 24 months of age
Risk factors include:
daycare attendance
parental smoking
immune dysfunction eg. HIV
congenital orofacial deformities (CLEFT PALLATE)
Pathogenesis/Causes of Otitis Media?
Pathogenesis
anatomic or physiologic eustachian tube dysfunction play a critical role in Ottis media
viral URTI => congestion / swelling of nasal mucosa, nasopharynx and eustachian tube
=> obstruction at eustachian tube isthmus (narrowest portion)
=> results in accumulation of middle ear secretions.
=> secondary bacterial infection of effusion causes suppuration
Causes
Viral URTI facilitates bacteria to ascend from nasopharynx
most common are:
Streptococcus pneumoniae (30-40%)
Non typeable H. influenzae (20%)
M. catarrhalis (10%)
Clinical Presentation/Investigation of Otitis Media?
Clinical Presentation
ear pain, ear drainage or decreased hearing is more common in older children.
occasionally vertigo and tinnitus
otoscopic examination reveals erythematous tympanic membrane which may be: Bulging, Retracted, Perforated
Investigation
tympanocentesis (needle aspiration of middle ear effusion)
not recommended unless patient is toxic, has failed multiple courses of antibiotics or immunosuppressed
swab cultures from external auditory canal do not accurately reflect cause
Imaging not helpful in diagnosis
Management of Otitis Media?
Management
- antibiotics should not be routinely prescribed initially!!
- delaying antibiotic therapy: reduces treatment-related costs and side-effects and minimizes emergence of resistant strains.
antibiotics deferred in:
healthy children older than six months of age w/ mild otitis media
in those the diagnosis is uncertain.
antibiotics recommended in
– all children younger than six months
– those between six months and two years if diagnosis is certain
– severe infection (severe otalgia or temperature > 39°C)
amoxicillin for 10 days is recommended first-line therapy
Pathogenesis/Clinical Presentation/Complications of Acute Mastoiditis?
Pathogenesis
infection in mastoid follows middle ear infection
hyperemia (Increased blood flow) and oedema of mucosal lining of air cells
=> serous and then purulent exudate.
=>blockage of antrum by inflamed mucosa prevents drainage of fluid
=> pressure of purulent exudate on thin bony septa
=> bone necrosis
Clinical
Early on resembles Acute Otitis Media
Later:
erythema, swelling and tenderness over mastoid bone
pinna displaced outward and downward
erythematous, bulging tympanic membrane
Complications
- hearing loss
- cranial nerve involvement
- osteomyelitis
- abscess formation
- intracranial extension– meningitis, cerebral abscess, epidural abscess, subdural empyema
Investigations/Management of Acute Mastoiditis?
Investigations:
plain radiographs may show increased opacification in mastoid region
ear drainage fluid for culture
– fresh pus as it exudes from tympanic membrane
– tympanocentesis if tympanic membrane not perforated
Management: amoxicillin for 10 days is recommended first-line therapy
___________ sinusitis more common than _________ sinusitis
Viral sinusitis more common than bacterial sinusitis - bacterial sinusitis a complication of viral URTI
Pathogenesis/Causes of Sinusitis?
3 key factors?
Pathogenesis related to three key factors:
- narrow sinus ostia => predispose to obstruction
- dysfunction of ciliary apparatus => structure/function of mucociliary apparatus impaired during viral colds
- viscous sinus secretions => impair ciliary function
Causes:
majority caused by viral infection
bacterial causes similar to agents that cause AOM
S. pneumoniae (30-40%)
nontypeable H. influenzae (20%)
M. catarrhalis (20%)
less frequently S. pyogenes (S. aureus and anaerobes)
rarely, f_ungal causes in immunocompromised_
Clinical Presentation/Predictors of Bacterial/Complications of Sinusitis
Clinical
young children– persistent rhinorrhoea (often purulent), Cough, foul breath, fever
older children and adults– symptoms and signs more localised to affected sinus
predictors of bacterial sinusitis include:
– symptoms persist for 10 days or longer
– persistent purulent nasal discharge w/maxillary tooth** or **unilateral facial pain
– unilateral sinus tenderness
– worsening symptoms after initial improvement
Complications
intracranial complications: subdural empyema, epidural abscess, brain abscess, meningitis, venous sinus thrombosis
extracranial complications:
orbital cellulitis: most common serious complication, associated with _ethmoiditis_
Orbital abscess
frontal and maxillary osteomyelitis
subperiosteal abscess
Investigations/Management of Sinusitis?
Investigations
Diagnosis is usually made on clinical grounds
Imaging if: vague symptoms, ambiguous physical findings, symptoms persist despite medical therapy
plain radiograph of sinuses: complete sinus opacification
maxillary sinus aspiration indicated in:
– lack of response to multiple courses of antibiotics
– orbital or intracranial complications
– immunocompromised patients
– nosocomial infection
Management
- amoxicillin first-line in mild disease and NO day-care**/ **NO previous antibiotic use– 10 to 14 day course
- amoxicillin-clavulanate or cefuroxime as second-line agents in severe disease, day-care exposure** or **previous antibiotic use.
Characteristics/Demographics of Epiglottitis?
Above the Glottis: locally invasive bacterial infection of epiglottis supraglottis structures (supraglottitis)
RESPIRATORY EMERGENCY: rapidly progressive (within hours) to severe upper airway obstruction
Most common in children aged 2-6 years with peak incidence in those aged 3 years
Causes/Clinical Manifestation of Epiglottitis?
Causes
Historically H. influenzae b – decreased dramatically since introduction of Hib vaccine
Now:
Streptococcus pneumoniae
group A or C streptococci
Clinical Manifestation
Abrupt onset of high fever, sore throat and odynophagia
stertor** and a **gurgling noise on inspiration
muffled voice (“hot-potato voice”) but not hoarse
marked tachycardia and tachypnoea
Physical Signs:
sits upright
hands extended behind body in a characteristic tripod position
jaw thrust forward, mouth open, and tongue protruding
Rapidly precedes to: fluctuating levels of consciousness and respiratory arrest
Investigation/Management of Epiglottitis?
Investigation: Swelling of epiglottis (thumb sign on XRAY)
Management
ensure child kept in upright position
a medical emergency
visualization of epiglottis must be performed with care - respiratory arrest may occur if there is laryngeal spasm while probing the mouth
direct examination should only be performed by trained personnel in a unit where immediate intubation or tracheotomy can be performed
laryngoscope examination reveals a “cherry-red” epiglottis
Characteristics/Demographics of Laryngotracheobronchitis( aka. _________)?
Laryngotracheobronchitis (Croup)
Bellow the glottis
subglottic inflammation caused by a viral or bacterial infection of larynx, trachea and bronchi.
most often in children aged 6 months to 6 years with peak incidence in second year.
Not expected in children >6 due to larger diameter of trachea and previous immunity
Most common infectious cause of obstruction of upper airway (stridor) in young children?
Laryngotracheobronchitis (Croup): inflammatory oedema of subglottic larynx and trachea, especially near cricoid cartilage => narrowing and obstruction of airway.
Leads to: stridor** (harsh, high-pitched **musical sound) produced by air flowing through narrowed subglottic area
Causes/Clinical Manifestation of Laryngotracheobronchitis (Croup)
Causes
Parainfluenza viruses types 1, 2, and 3 are most common causes
RSV
Influenzas A and B
Clinical Manifestation
Starts as nonspecific URTI symptoms
Within 1-2 days hoarseness of voice is followed by paroxysms of brassy or barking, non-productive cough** that ends with a **prominent inspiratory stridor.
In more severe cases: Tachypnoea, use of accessory respiratory muscles
Self-limiting in most children
Sometimes leads to larygeal obstruction/ respiratory failure
Diagnosis/Management of Croup?
Diagnosis: anterior-posterior and lateral neck X-rays may help to differentiate croup from other causes of stridor.
Lateral neck X-rays show:
ballooning of hypopharynx
subglottic narrowing
normal epiglottitis
Management
- Minimal handling to avoid worsening symptoms.
- Keep children with carers to reduce distress.
- Mild/Moderate croup treated with steroids alone.
- Severe croup requires nebulized adrenaline** and **steroids.
