URTI

Question 1

types of URTIs

Answer 1

1. common cold
2. influenza
3. pharyngitis
4. rhinosinusitis
5. laryngitis
6. otitis media

Question 2

clinical presentation of pharyngitis

Answer 2

1. acute onset of sore throat
2. pain with swallowing
3. fever
4. erythema and inflammation of pharynx and tonsils (may have patchy exudates)
5. tender and swollen lymph nodes

Question 3

microbiology of pharyngitis

Answer 3

> 80% viral:

• rhinovirus
• coronavirus
• influenza
• parainfluenza
• epstein-barr

<20% bacterial:
- beta-hemolytic streptococcus pyogenes

Question 4

pathogenesis of pharyngitis

Answer 4

• direct contact with droplets of infected saliva or nasal secretion
• short incubation of 24-48h

Question 5

complications of S.pyogenes in pharyngitis

Answer 5

1. acute rheumatic fever (prevented w early initiation of Abx)
2. acute glomerulonephritis (not prevented by Abx)

Question 6

benefit of Abx in bacterial pharyngitis

Answer 6

1. prevent acute rheumatic fever
2. shorten duration of symptoms by 1-2d
3. reduce transmission (no longer infectious after 24h of antibiotics)

Question 7

diagnostic test for S.pyogenes pharyngitis

Answer 7

1. throat culture (24-48h)
   - gold standard
   - 90-95% sensitive
2. rapid antigen detection test RADT (minutes)
   - 70-90% sensitive

Question 8

modified centor criteria for S.pyogenes pharyngitis

Answer 8

• fever >38 (1)
• swollen, tender anterior cervical lymph nodes (1)
• tonsillar exudate (1)
• absence of cough (1)
• 3-14yo (1)
• > = 45yo (-1)

Question 9

point evaluation for centor criteria

Answer 9

0-1: no additional testing indicated; low risk; presumed viral

2-3: test for S.pyogenes pharyngnitis or initiate empiric tx

4-5: high risk for s.pyogenes, initiate empiric

Question 10

tx for s.pyogenes pharyngitis`

Answer 10

first line: Penicillin VK 
alternative:
- amoxi
- cephalexin
- clinda
- clarithro
duration: 10d
clinical response within 24-48h

Question 11

rhinosinusitis major symptoms

Answer 11

1. purulent anterior nasal discharge
2. purulent/ discolored posterior nasal discharge
3. nasal congestion/ obstruction
4. facial congestion/ fullness
5. facial pain/pressure
6. hyposmia/ anosmia
7. fever

Question 12

minor symptoms of rhinosinusitis

Answer 12

1. headache
2. ear pain, pressure, fullness
3. halitosis
4. dental pain
5. cough
6. fatigue

Question 13

clinical determination of sinusitis

Answer 13

> = 2 major symptoms or 1 major + >=2 minor symptoms

Question 14

microbiology of sinusitis

Answer 14

viral (>90%):

• rhinovirus
• adenovirus
• influenza
• parainfluenza

bacterial (<10%):

• strepto pneumoniae
• haemophilus influenzae
• also moraxella catarrhalis
• also strepto pyogenes

Question 15

pathogenesis of sinusitis

Answer 15

• direct contact w droplets of infected saliva or nasal secretions
• bacterial cases usually preceded by viral URTI (common cold, pharyngitis)
• inflammation results in sinus obstruction

Question 16

limitation in diagnostic test for sinusitis

Answer 16

• viral and bacterial symptoms very similar
• imaging studies: non-specific, non-discriminatory
• sinus aspirate (gold standard test): invasive, painful, time consuming

Question 17

clinical diagnosis of bacterial sinusitis

Answer 17

presence of any one:

1. persistent symptoms >10d and not improving
   - viral tend to be self limiting and resolved ~7-10d
2. severe symptoms at onset
   - purulent nasal discharge x 3-4d
   - high fever >=39 degree
3. double sickening:
   - worsening symptoms after 5-6d after initial improvement

Question 18

tx for bacterial sinusitis

Answer 18

first line:

• amoxi
• amoxi clav

alternative:
- respi FQ (levo/moxi)
- cotrimoxazole
- 2nd gen cephalo (cefixime, cefuroxime)

duration: adults 5-10d, peds: 10-14d

Question 19

why are macrolides and tetracyclines not suitable for sinusitis

Answer 19

s. pneumoniae highly res to them (clarithro, azithro, doxy)

Question 20

why is ciprofloxacin not used?

Answer 20

poor respi FQ, poor activity against strep pneumoniae

Question 21

tx consideration for sinusitis

Answer 21

Strepro pneumoniae res

• multi step penicillin-binding protein mutation
• increase penicillin MIC
• prefer high amoxi>pen (pk better)

haemophilus influenzae res:

• beta lactamase production
• inhibited by beta-lactams inhibitor

Question 22

consideration for amoxi dosing for strepto pneumoniae res

Answer 22

• amoxi preferred over pen (better pk)
• high dose amoxi preferred

normal amoxi: 45mg/kg OD (peds); 250-500mg (Adults)
high dose amoxi: 80-90mg/kg OD (peds), 1g (adults)

Question 23

when to use amoxi clav in sinusitis

Answer 23

if haemophilus res use amoxi/clav when either:

• recent course of antibiotics
• recent hospitalisation
• failure to imrpove after 72h of amoxi

Question 24

acute otitis media signs and symptoms

Answer 24

1. ear pain (otalgia)
2. ear discharge (otorrhea)
3. ear popping
4. ear fullness
5. hearing impairment
6. dizziness
7. fever
8. non-specific in young infants: ear rubbing, excessive crying, changes in sleep pattern

Question 25

risk factors of AOM

Answer 25

1. sibling 2. attending day care 3. supine position during feeding 4. exposure to tobacco 5. pacifier use 6. winter

Question 26

prevention of AOM

Answer 26

1. avoid exposure to tobacco 2. exclusive breast feeding 1-6mth 3. minimize use of pacifier 4. vaccinations (influenza, pneumococcal, haemophilus)

Question 27

pathogenesis of AOM

Answer 27

1. viral URTI (common cold) 2a. nose sniffing: leading to reflux of secretions into middle ear 2b. secretions and inflammation 3. eustachian tube obstruction 4. negative eustachian tube pressure: leading to reflux of secretions into middle ear providing a medium for bacteria accumulation and growth

Question 28

microbiology of AOM

Answer 28

bacterial (55-60%): - strepto pneumoniae - haemophillus influenzae - moraxella catarrhalis viral (40-45%): - respiratory syncytial virus - rhinovirus - adenovirus - parainfluenza virus

Question 29

AOM diagnosis

Answer 29

1. pneumatic otoscope (standard tool) 2. acute onset (<48h) 3. otalgia (holding, tugging, rubbing in non-verbal child) / erythema of tympanic membrane) 4. bulging of tympanic membrane

Question 30

challenges in management of AOM

Answer 30

- unable to distinguish bacterial vs viral etiologies

Question 31

when to consider observation period instead of starting tx

Answer 31

1. pt >= 6mth old 2. non severe illness (no mod-severe otalgia, no otalgia >=48h, no fever >39 degree in last 48h) 3. no otorrhea 4. possible for close follow up

Question 32

AOM tx timeline

Answer 32

1. <6mth old: immediate abx 2. 6mth-12yo: immediate abx, (if only unilateral AOM w/o otorrhea can consider observation first) 3. >2yo: - immediate abx for AOM with otorrhea/severe symptoms - uni/bi lateral AOM w/o otorrhea can consider observation first

Question 33

what is observation period

Answer 33

observation period: supportive care 48-72h - if improve: no Abx - if worsens of fail to improve: start Abx

Question 34

AOM tx

Answer 34

first line: amoxicillin if: 1. no amoxicillin last 30d & 2. no concurrent purulent conjunctivitis & 3. no pen allergy alternative first line : amoxi/clav if: 1. amoxi taken in last 30d or 2. concurrent purulent conjunctivitis or 3. Hx of AOM non-responsive to amoxi alternative: 1. cefuroxime/ ceftriazone IM (mild pen allergy) 2. Clindamycin (only good against s.pneumoniae)

Question 35

criteria for improvement of AOM

Answer 35

improvement expected in 28-72h

Question 36

duration of tx

Answer 36

<2 yo or severe symptoms (mod-severe symptoms): 10d duration 2-5yo + severe symptoms : 7d duration >=6yo + non severe symptoms: 5-7d duration