URTI l (pharyngitis, sinusitis & AOM) Flashcards
What is used to diagnose bacterial pharyngitis?
Modified Centor Criteria
0-1 = likely viral
2-3 = moderate risk, can initiate empirical therapy or culture
4-5 = high risk, initiate empirical therapy
Treatment for bacterial pharyngitis
1st line : Penicillin VK (PO) Alternatives : - amoxicillin - cephalexin - clarithromycin - clindamycin
Pathogens of bacterial pharyngitis
Group A beta-hemolytic Streptococcus pyogenes
Complications of bacterial pharyngitis
1-3 weeks
- Acute rheumatic fever (can be prevented from using antibiotics early)
- Acute glomerulonephritis (cannot be prevented even with antibiotics)
Pediatric doses for bacterial pharyngitis
- Penicillin VK (250mg BD/TDS)
- Amoxicillin (40-50mg/kg/day divided BD)
- Cephalexin
- Clindamycin (7mg/kg/dose TDS)
Duration = 10 days
Adult doses for bacterial pharyngitis
- Penicillin VK (250mg QDS or 500mg BD)
- Amoxicillin (1g OD or 500mg BD)
- Cephalexin
- Clindamycin (300mg TDS)
Duration = 10 days
Presence of sinusitis
Major (7)
- Purulent anterior nasal discharge
- Purulent or discolored posterior nasal discharge
- Facial congestion/fullness
- Nasal congestion/obstruction
- Facial pain/pressure
- Hyposmia/anosmia
- Fever
Minor (6)
- Fatigue
- Dental pain
- Halitosis
- Headache
- Ear pain/pressure/fullness
- Cough
Sinusitis only if :
- At least 2 majors
- 1 major & at least 2 minors
Bacterial sinusitis diagnosis
Presence of sinusitis only :
At least 2 majors
1 major & at least 2 minors
Bacterial if (any) :
- Persists for >10days
- Severe symptoms onset (purulent discharge x3-4 days or high fever >39)
- Worsening symptoms (appear 5-6 days after improvement)
Treatment for bacterial sinusitis
1st line : Amoxicillin or Amoxicillin/clavulanate
- amox/clav only if :
1. recent antibiotics use
2. recent hospitalisation
3. non-responsive to amoxicillin after 72h
Alternatives :
- respiratory fluoroquinolones (levofloxacin/moxifloxacin)
- co-trimoxazole (trimethoprim & sulfamethoxazole)
- 2nd gen cephalosporin (cefuroxime)
Duration :
5-10 days (adult)
10-14 days (children)
Pathogens of bacterial sinusitis
- Streptococcus pneumoniae
2. Haemophilus influenzae
Why is ciprofloxacin not considered a respiratory fluoroquinolone?
Ciprofloxacin has poor activity against Streptococcus pneumoniae
Do we use normal doses of amoxicillin for bacterial sinusitis?
No because Streptococcus pneumoniae have resistance to penicillins through a multistep penicillin-binding protein(PBP) mutations, increasing MIC value.
- amoxicillin > penicillin due to better PK profile (higher F)
- use high dose amoxicillin
adult dose = 1g TDS
pediatric dose = 80-90mg/kg/day divided BD
Haemophilus influenzae resistance
Due to beta-lactamase production, thus require beta-lactamase inhibitor (clavulanate)
Hence, use amoxicillin-clavulanate
1. recent antibiotic use
2. recent hospitalisation
3. failure to improve 72h after initiation of amoxicillin
Risk factors for AOM (7)
- Siblings
- Attending daycare
- Supine position during feeding
- Tobacco smoke exposure at home
- Pacifier use
- Winter season
- Age <5y/o
Prevention of AOM
- Avoid tobacco smoke exposure at home
- Exclusive breastfeeding for first 6months (pass maternal antibodies to infants to prevent viral URTI)
- Vaccinations (influenza, haemophilus influenzae type B & pneumococcal)
- Minimise pacifier use
Pathogens of AOM
Bacteria > Viral
- Streptococcus pneumoniae
- Haemophilus influenzae
- Moraxella catarrhalis
Why are children <5y/o more prone to AOM?
They have shorter and straighter eustachian tube.
Eustachian tube connects the nasopharynx and middle ear to regulate middle ear pressure.
Viral URTI leads to backflow and accumulation of nasal discharge into middle ear, providing medium for the growth and multiplication of bacterial, leading to AOM
Diagnosis of AOM
Use tympanic otoscope to look for :
- erythema of tympanic membrane
- bulging of tympanic membrane
AOM
- acute onset (<48h)
- otalgia (pain in the ears)
When to initiate empirical treatment or observe?
Observatory period can if :
- at least 6months
- non-severe illness (severe if moderate-severe otalgia, otalgia for 48h, high fever >39 in last 48h)
- no otorrhea
- close monitoring possible
- shared decision making w the parent/caregiver
Treatment criteria for AOM
<6months : no observatory period, have to initiate empiric treatment
6months-2y/o :
observatory period only if unilateral AOM w/o otorrhea
> =2y/o :
observatory period for unilateral/bilateral AOM w/o otorrhea
ALL AGES :
initiate empiric treatment if otorrhea or severe symptoms
Treatment for AOM
1st line : Amoxicillin or Amoxicillin/clavulanate amoxicillin if : - no amoxicillin within 30 days - no concurrent purulent conjunctivitis - no penicillin allergies
amox/clav only if :
- recent amoxicllin use within 30days
- concurrent purulent conjunctivitis
- history of AOM non-responsive to amoxicillin
Alternatives :
- Cefuroxime PO or Ceftriaxone IM (mild penicillin allergies)
- Clindamycin (severe penicillin allergies)
When do we consider high dose of amoxicillin?
Sinusitis and AOM
This is because Streptococcus develop resistance against penicillins through a multistep penicillin-binding protein mutations, increasing MIC for penicillins.
Pediatric higher dose = 80-90mg/kg divided BD
Adult higher dose = 1g TDS
Duration of treatment for AOM
<2y/o = 10 days Severe symptoms (high fever >39 within 48h, otalgia for at least 48h, moderate-severe otalgia) = 10 days 2-5y/o = 7 days >6y/o = 5-7 days
Pediatric dose for AOM
- Amoxicillin (80-90mg/kg divided BD)
- Amoxicillin/clavulanate (80-90mg/kg divided BD)
- Cefuroxime (30mg/kg/day divided BD)
- Ceftriaxone
- Clindamycin
Pediatric dose for bacterial sinusitis
- Amoxicillin (80-90mg/kg divided BD)
- Amoxicillin/clavulanate (80-90mg/kg divided BD)
cannot levofloxacin or moxifloxacin
Adult dose for bacterial sinusitis
- Amoxicillin (1g TDS)
- Amoxicillin/clavulanate (625mg TDS or 1g BD)
- Levofloxacin 500mg OD
- Moxifloxacin
- Co-trimoaxazole
- Cefuroxime
What antibiotics cannot be used for Streptococcus pneumoniae?
Tetracyclines and macrolides due to resistance.
Mainly clarithromycin & azithromycin, and doxycyclines.
Period for Acute Sinusitis
Within 4 weeks
How long should observatory period for AOM be?
48-72h. Start antibiotics if condition worsens or fails to improve.
