URTI Flashcards
Acute otitis media (AOM) pathophysiology
Preceded by a viral URTI → dysfunction of eustachian tube and mucosal swelling of middle ear Reflux of bacteria/viruses and fluid from nasopharynx into middle ear → not cleared properly by mucociliary system
Children more susceptible due to anatomy of eustachian tube (shorter and more horizontal)
AOM Risk factor
Winter season outbreaks of viral infections
Episode of acute otitis media in first 6 months of life Sibling with a history of recurrent otitis media Exposure to tobacco smoke in home
Attendance at a daycare centre
Pacifier use
MIrcobiology AOM
Viruses (40-45%) Respiratory syncytial virus (RSV) Rhinovirus Adenovirus Parainfluenza virus
Bacteria Streptococcus pneumoniae Haemophilus influenzae Moraxella catarrhalis Staphylococcus aureus Streptococcus pyogenes
CLinical presentation of AOM
Fever , Natural history --- Resolves over ~ 1 week Tugging at Ear Acute onset Runny nose, nasal congestion, cough earpain (otalgia) Difficulty sleeping
Diagnosis of AOM
Diagnostic criteria
Children who present with moderate to severe bulging of tympanic membrane (TM), or new onset otorrhea not due to acute otitis externa
OR
Children who present with mild bulging of TM and recent (< 48hrs) onset of ear pain (holding, tugging, rubbing of the ear in a nonverbal child) or intense erythema of TM)
Physical examination
- Otoscope
Discolored or reddened tympanic membrane Thickened tympanic membrane
Bulging tympanic membrane
Culture of middle ear fluid (natural or drain)
Diagnosis of AOM
No gold standard for diagnosis
Signs and symptoms very non-specific
Young children cannot verbalize symptoms
Diagnosis of AOM
No gold standard for diagnosis
Signs and symptoms very non-specific
Young children cannot verbalize symptoms
Types of Treatment for AOM
Non-antibiotic/Supportive treatment
Paracetamol or NSAID’s for pain and fever
Decongestants and antihistamines not shown to affect outcome
Topical analgesics not recommended
Surgical insertion of tympanostomy tubes (Ttubes)
- Allows drainage of middle ear fluid
- Only for children with recurrent episodes
- 3 episodes in 6 months, or
- 4 episodes in 1 year, with 1 episode in the preceding 6 month - Observation Period (Delayed Treatment)
- Wait and See Prescription (WASP)
- Immediate Treatment
AOM controversy
Use of antibiotic ear drops not recommended
- Local adverse effects
- Contribute to development of resistance
~ 80% of cases will resolve within 3 -4 days without antibiotics
Over-prescribing of antibiotics may contribute to development of resistance and risk of adverse effects Immediate antibiotic treatment results in ~ 1 day faster resolution of illness
AOM controversy
Use of antibiotic ear drops not recommended
- Local adverse effects
- Contribute to development of resistance
~ 80% of cases will resolve within 3 -4 days without antibiotics
Over-prescribing of antibiotics may contribute to development of resistance and risk of adverse effects Immediate antibiotic treatment results in ~ 1 day faster resolution of illness
Observation Period (Delayed Treatment) AOM
No antibiotics
Symptomatic treatment for initial period of 48- 72 hours
If child improves → do not give antibiotics
If no improvement, or worsening → start antibiotics Must ensure appropriate follow-up and have reliable parents
Disadvantage –may need a second physician visit
Wait and See Prescription (WASP) AOM
Initial physician visit → give parents prescription for antibiotic
But, fill prescription only if no improvement in 48 hours
Reduces antibiotic use (~ ⅔ of prescriptions not filled) Parents satisfied with this approach
More convenient than second physician visit
Immediate Treatment AOM
Immediate Treatment
At the time of diagnosis → start antibiotic
More convenient
Expected by parents?
types of AOM
Otorrhea with AOM
Unilateral or Bilateral AOM with Severe Symptoms
Bilateral AOM without Otorrhea
Unilateral AOM without Otorrhea
Tx principle for types of AOM
Otorrhea with AOM
Unilateral or Bilateral AOM with Severe Symptoms
- ABX therapy
Bilateral AOM without Otorrhea
- 6 months to 2 years = ABX therapy
- > = 2years = Antibiotic therapy, OR Observation period
Unilateral AOM without Otorrhea
= Antibiotic therapy, OR Observation period
Definition of severe and non severe illness in AOM
Severe illness
- Moderate to severe otalgia OR
- otalgia for ≥48 hours OR
- temperature ≥ 39°C in the past 48 hours
Non-severe illness
- Mild otalgia for < 48 hours AND temperature < 39°C
Infants < 6 months of age
Specifically excluded from 2013 guidelines
2004 guidelines →immediate antibiotic therapy Observation period not recommended in this age group
AOM
Infants < 6 months of age
Specifically excluded from 2013 guidelines
2004 guidelines →immediate antibiotic therapy Observation period not recommended in this age group
AOM
Abx for AOM first choice
Amoxicillin
Drug of first choice
Patient has not received amoxicillin in past 30 days,
AND
Does not have concurrent purulent conjunctivitis, AND
Not allergic to penicillin
Dose
- Children = 80-90mg/kg/day divided every 12 hours
- Adults = 500mg –1g tds
AOM alternative first line therapy
Amoxicillin-clavulanate
Alternative first-line therapy
Patient has received amoxicillin in past 30 days, OR Has concurrent purulent conjunctivitis, OR
Has a history of recurrent AOM unresponsive to amoxicillin
Abx for AOM if patient have taken ABX in previous month
Taken antibiotics in the previous month
High dose amoxicillin
Cefuroxime = 30mg/kg/day divided every 12 hours Bad taste may affect compliance
Second or third generation oral cephalosporins Need to cover more resistant β-lactamase producing organisms
duration of therapy for AOM
Depends on age of child and severity of infection
< 2 years of age = 10 days
Severe symptoms = 10 days
2 –5 years of age with mild to moderate AOM = 7 days
≥6 years of age with mild to moderate AOM = 5 –7 days
tx failure for AOM alternative
No response after 48 –72 hours → treatment failure → change antibiotics
Amoxicillin-clavulanate
Ceftriaxone IM or IV 50mg/kg daily (maximum 1g) x 3 days
Other second or third generation oral cephalosporins
Penicillin-allergic patients AOM
Second or third generation oral cephalosporin, OR ceftriaxone (IM/IV)
Severe, immediate hypersensitivity reaction in AOM what tx
less severe rxn then?
Azithromycin, clarithromycin
Clindamycin –only for documented Strep. pneumoniae
Less severe reaction
- Cephalosporins
Prevention of Acute Otitis Media
Recommended strategies
- Eliminating exposure to tobacco smoke
- Breastfeeding for first 6 months of life
- Eliminating pacifier use in second 6 months of life
Vaccinations
- Influenza vaccine (Decreases incidence by ~30%)
- Pneumococcal vaccine
(6% reduction in incidence AND Decreases need for T-tubes, number of office visits and decreased antibiotic prescriptions)
Sinusitis
Inflammation and/or infection of the paranasal sinus mucosa (and usually also involves nasal mucosa)
CLassification of sinusitis
Acute –symptoms last < 4 weeks
Subacute –symptoms last 4 –12 weeks
Chronic –symptoms persist > 12 weeks
pathophysiology of acute bacterial sinusitis
Usually preceded by a viral upper respiratory tract infection that causes mucosal inflammation Inflammation results in obstruction of sinus ostia Mucosal secretions are trapped, local defenses impaired, and bacteria trapped and can multiply and set up infection
Risk factor for sinusitis
Dental infection or extraction
Allergic rhinitis
Swimming Prior URTI Asthma Cigarette smoking Environmental pollution Mechanical ventilation Anatomic abnormalities –adenoids, deviated nasal septum, nasal polyps Nasogastric (NG) tubes
microbiology
virus and bacterial
Usually a single organism
With increasing use of pneumococcal vaccine → increase in prevalence of H. influenzae and Moraxella
Clinical presentation of acute sinusitis
acute bacterial sinusitis
Acute sinusitis Nasal congestion Facial/sinus pain or pressure Nasal discharge Fever Tooth pain Reduced sense of smell (hyposmia) Malaise
Viral infection –usually resolves within 7 –10 days
Acute bacterial rhinosinusitis
Persistent signs and symptoms of acute rhinosinusitis for ≥ 10 days without evidence of clinical improvement, OR
Symptoms or signs of acute rhinosinusitis worsen within 10 days after initial improvement (double worsening)
Diagnosis for acute bacterial sinusitis
Primarily a clinical diagnosis
Other investigations
Aspiration and culture of fluid from sinuses
- Gold standard
- Requires skill and experience
X-ray of sinuses
Ultrasound of sinuses
CT or MRI of sinuses
- Only if suspecting complications
Course of disease ABS
40-60% recover spontaneously within 7 –10 days (likely viral)
If persists longer than 7 –10 days → more likely bacterial
- Primary bacterial
- Secondary bacterial –after a viral infection
Tx for ABS
Symptomatic/adjunctive
- Analgesics
- Antihistamines and decongestants
A) Not recommended in guidelines (vs. practice)
B) No objective evidence of benefit vs. risk of adverse effects
- Irrigation of nasal sinuses with saline
A) Recommended as adjunctive therapy for both adults and children
ICS for ABS
mometasone
budesonide
flunisolide
fluticasone
Steroids may reduce nasal and sinus mucosal inflammation and facilitate drainage of sinuses
Steroid plus antibiotic more effective than antibiotic alone
Some evidence of a dose-response relationship
- recommended for symptomatic relief of acute bacterial rhinosinusitis (ADULT)
Abx therapy for ABS
May be a small benefit with faster resolution of symptoms
May prevent progression to chronic sinusitis and complications
Amoxicillin alone OR amoxicillin/clavulanate
Dosing
Low dose = 45mg/kg/day in 2 divided doses
High dose = 80 –90mg/kg/day in 2 divided doses (high dose for Areas with high prevalence of non-susceptible Strep pneumoniae isolates)
Second-line antibiotics
- If suspect that patient is at risk for having a resistant organism
EG Recent course of antibiotics, recent hospitalization, local resistance patterns, etc., OR
- Failure to improve within 72 hours with amoxicillin
Amoxicillin/clavulanate
Second or third generation oral cephalosporins Fluoroquinolones –levofloxacin (adults only) Doxycycline (adults only)
Penicillin-allergic patients - Immediate-type hypersensitivity A) Clarithromycin, azithromycin B) Cotrimoxazole C) Fluoroquinolone D) Doxycycline
Minor reaction
A) Oral cephalosporins
Abx therapy principle ABS
Watchful waiting (without antibiotic), OR
Immediate antibiotic therapy
Watchful waiting
Start antibiotic if no improvement by 7 days, OR
if condition worsens at any time
Amoxicillin alone OR amoxicillin/clavulanate Recommend high dose amoxicillin over standard dose
Duration of therpy for ABS
adults: 5 –10 days
Lower incidence of adverse effects with shorter duration
Children
10 –14 days
Pharyngitis bacteria
Group A β-hemolytic Streptococcus (Streptococcus pyogenes)
80% is virus caused
pharyngitis epidemiology
Children 5 –15 years of age at greatest risk
Rare in adults > 30 years of age
Seasonal outbreaks
clinical presentation of pharyngitis
Sore throat Headache Abdominal pain Red, swollen uvula Pain on swallowing Enlarged, tender cervical lymph nodes Nausea and vomiting Erythema/inflammation of tonsils and pharynx (with or without patchy exudates) Runny nose Fever Cough
diagnosis of pharyngitis
Difficult to distinguish viral from bacterial cause based on clinical presentation
Age of patient
Contact history or outbreaks in area
Throat swab/culture
- Gold standard for diagnosis
- 24 –48 hours for results
Rapid antigen detection testing
- Based on immunoassay
- Results within minutes
- Can be done in GP office setting
IDSA guidelines (2012)
- Rapid antigen detection test and/or culture should be done to confirm diagnosis
- Cannot rely on clinical features to distinguish bacterial from viral infection
Clinical scoring systems (Centor criteria)
for pharyngitis
1 point each for Fever Tonsillar exudates Swollen, tender anterior cervical lymph nodes Lack of cough
MOH guidelines (2006)
- Score < 3 → no antibiotics - Score 3 or 4 → treat with antibiotic
US-based guidelines
- Score 0 or 1 → no further diagnostic testing, no antibiotics - Score 2, 3 or 4 → rapid antigen test → antibiotic if positive
complication of pharyngitis
Viral infection –self-limited
Group A Streptococcus infection
- Acute rheumatic fever (rheumatic heart disease)
(Rare in developed countries)
- Acute glomerulonephritis
- Develop 1 –3 weeks after infection
- Antibiotic treatment will prevent acute rheumatic fever, but does not prevent glomerulonephritis
symptomatic tx for pharyngitis
Paracetamol NSAID’s Corticosteroids Lozenges Adequate fluid intake Adequate rest
abx tx forpharyngitis
Amoxicillin or Penicillin x 10 days
Other treatment options (low / standard dose)
First or second generation oral cephalosporins Azithromycin/clarithromycin –penicillin allergic Clindamycin –penicillin allergic
Recommend 10 day course of therapy except azithromycin
Amoxicillin dosing - Standard dosing = 25mg/kg bd - Once daily dosing 50mg/kg (maximum 1g) 10 days duration As effective as penicillin and divided dose amoxicillin
pharyngitis
Use of antibiotics shortens symptoms by ~1 – 2 days Considered significant enough to warrant treatment Prevents transmission to others and development of complications
No longer contagious after 24 hours of treatment
pharyngitis
Use of antibiotics shortens symptoms by ~1 – 2 days Considered significant enough to warrant treatment Prevents transmission to others and development of complications
No longer contagious after 24 hours of treatment
