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1

list the URTIs we are required to know

1. common cold
2. pharyngitis
3. croup
4. pertussis
5. otitis media
6. sinusitis

2

what is the common cold

it is a VIRAL URTI

acute and self limiting

most frequent human illness

seasonal

3

how is the common cold transmitted

most significant = inoculation of conjunctiva or nasal mucosa in 10 seconds

less significant is infective droplets on mucosa

4

when and for how long is the common cold infective

viral shedding peaks on the third day (coincides with peak of symptoms)

low level shedding can persist for 3 weeks

5

what is the incubation period of the common cold

24-72 hours from contact to symptoms

6

list some viruses that cause the common cold

1. rhinovirus
2. RSV
3. influenza virus
4. parainfluenza virus
5. adenovirus
6. enterovirus (coxsackievirus, echovirus)
7. coronavirus
8. human metapneumavirus

7

which viruses usually cause the common cold in october/november

parainfluenza virus

8

which virus is mostly responsible for the common cold in may/june/july/aug

enterovirus (coxsackievirus and echovirus)

9

which virus is mostly responsible for the common cold in september and march/april

rhinovirus

10

which viruses are mostly responsible for the common cold in dec/jan/feb

influenza, RSV, coronavirus, adenovirus

11

pathophysiology of the common cold

virus deposits on nasal/conjunctival mucosa and attaches to the epithelial cell receptors and damages cells--> this results in activation of host defence and release of CYTOKINE IL8

IL-8 attracts PMNs which increase nasal secretion and decrease mucociliary clearance

severity of symptoms corresponds to IL-8

12

pathophysiology of rhinovirus (common cold)

release of ALBUMIN and BRADYKININS which cause increased vascular permeability

bradykinins cause sore throat and rhinitis

minimal damage to nasal epithelium (like coronavirus)

13

pathophysiology of adenovirus and influenza A (common cold)

CYTOPATHIC effect and DESTRUCTION of nasal epithelium

14

how do you diagnose the common cold

differential

15

clinical presentation of the common cold

rhinorrhea
nasal congestion
sneezing
sore throat
cough
low grade fever
headache
malaise

duration = 10 days (cough may last 2-3 weeks)

16

Tx of common cold

prevention-based (i.e hand washing)

symptomatic treatment
saline irrigation
decongestants (dont shorten duration)
steam inhalation
antipyretic/pain control

17

what is pharyngitis

one of most common reasons for physicians visits

majority are VIRAL

swelling of the back of the throat/pharynx, between the nostrils and larynx

18

epidemiology of pharyngitis

peak incidence in winter and early spring

mostly school aged kids

GAS pharyngitis:
-20-30% in kids//5-15% in adults
-incubation period of 2-5 days
-highly communicable but noninfectious within 24 hours of abs use
-transmission via droplet person to person

19

viruses that cause pharyngitis

1. respiratory viruses
-adenovirus
-influenza virus
-parainfluenza virus

2. other viruses
-coxsackie virus
-echovirus
-HSV
-epstein barr

20

bacteria that cause pharyngitis

*Strep pyogenes (GAS) "strep throat"

groups C and G strep
N. gonorrhea
corynebacterium diphteriae
fusobacterium necrophilum
arcanobacterium hemolyticum

21

pathophysiology of GAS pharyngitis + virulence factors

(S. pyogenes)

-URT colonization (highly virulent)
-capsule = compromised of HYALURORIC ACID which has a chemical structure very similar to connective tissue and therefore escapes host defenses and allows for colonization

virulence factors:
1. M proteins--> resist phagocytosis
2. extracellular exotoxins/hemolysins/invasins--> tissue damage
3. streptolysin O --> toxic to variety of cells including myocytes (causes rheumatic fever in 3% of untreated patients)

22

with what symptoms of pharyngitis do you suspect viral etiology

COUGH

hoarseness
conjunctivitis
rhinorrhea
diarrhea
rash

*do not test children and adults with signs and symptoms of viral etiology

23

when do you suspect GAS as the etiologic agent in pharyngitis (symptoms)

ABSENCE OF COUGH

pharyngeal/tonsillar exudate
tenderness/enlargement of anterior cervical lymph nodes

24

what might you suspect when pharyngitis in a teen or young adult presents with:
1. neck pain
2. rash

1. Lemierre's disease (fusobacterium necrophorum)
2. consider arcanobacterium haemolyticum

25

pharyngitis diagnosis procedure

throat culture (90-95% sensitive for GAS)

rapid antigen test (highly specific; sensitivity 70-90%)

confirmatory culture of RADT is negative in children

26

Tx of pharyngitis
1. viral
2. bacterial

1. symptomatic
2. if GAS, penicillin (alternative is clindamycin)

27

what is croup

laryngotracheitis (inflammation of larynx and trachea)

self limiting infection

28

in what age range is croup most common

3-36 months (rare after that)

29

in what sex is croup most common

boys

30

when is croup most common

fall/winter (coincides with parainfluenza, influenza, RSV)

31

when in the day are croup symptoms most prominent

late evenings and early mornings (leading to ER visits)

32

is croup viral or bacterial

viral

33

what types of viruses cause croup

**parainfluenza type 1

RSV
adenovirus
coronavirus
influenza (rare but more severe)
measles (in endemic areas)
rhino/enterovirus (mild cases)

34

pathophysiology of croup

viral infection of nasal pharyngeal mucosa-->invasion of respiratory epithelium --> inflammation of CARTILAGINOUS SUBGLOTTIC REGION --> narrowing of trachea --> fibrinous exudates may worsen the narrowing

host factors = genetic predisposition, anatomic narrowing, hyperactive airways

35

what is the hallmark of croup in infants

barking cough

36

clinical presentation of croup

infants: barking cough

stridor, cough, hoarseness

in older children, hoarseness is a prominent symptom

typical presentation = sudden onset of symptoms, rapidly progressive, previous Hx of croup

37

how is croup diagnosed

DDx

38

Tx of croup

NOT antibiotics because its viral

systemic/nebulized STEROIDS

symptom Tx

severe presentations can require nebulized epinephrine, blow-by O2 if hypoxic

39

transmission of pertussis

direct contact of inhalation of respiratory droplets

incubation is 7-10 days (or 4-21 depending on source)

40

what causes pertussis

*Bordatella pertussis

obligate human pathogen
fastidious gram - coccobacilli

other strains of bordatella that can cause pertussis are: B. parapertussis, B. bronchoseptica and B. holmesii (severe)

41

pathophysiology of pertussis

B. pertussis produces toxic and virulence factors-->
adhesins
tracheal cytotoxin/dermonecrotic toxin

these toxins cause local tissue damage and interfere with host immune mechanisms

endotoxins --> systemic manifestations and lymphocytosis

organisms found in ALVEOLAR MACROPHAGES and CILIATED RESPIRATORY EPITHELIAL CELLS

42

describe the classical clinical manifestations of pertussis

"whooping cough"

paroxysmal cough
inspiratory whoop
post-tussive emesis

adolescents and adults have milder symptoms (protracted cough, considerable morbidity, important reservoir)

43

what are the 3 phases of pertussis

1. catarrhal (1-2 weeks, most contagious)
2. paroxysmal (3-6 weeks)
3. convalescent (>6 weeks)

investigations you order depend on lengths of symptoms
cough 3 weeks= B. pertussis PCR

44

Tx of pertussis

antobiotics = MACROLIDE (azythromycin, clarithromycin, erythromycin) or TMP-SMX

if started in catarrhal phase, Abs reduce duration and severity of the disease and limit transmission (after this phase, only transmission is limited)

45

vaccination schedule for pertussis

2, 4, 6 months; 18 months; 4-6 years; grade 9

46

what is otitis media

inflammatory disease of the middle ear

47

at what age is otitis media most prevalent

infancy

60-80% of kids have episode within first year
80-90% by 2-3 years

48

in what sex is otitis media most prevalent

boys

49

what vaccine has reduced the incidence of otitis media

pneumococcal vaccine

50

risk factors for otitis media

1. age 6-18 months
2. family Hx
3. day care
4. lack of breastfeeding
5. tobacco smoke/air pollution
6. pacifier use
7. race/ethnicity
8. poverty

51

what normally causes otitis media

66% of patients have combined viral and bacterial infections

S. pneumo = 50%
H. influenzae = 40-45%
M. catarrhalis>S. pyogenes>staph aureus

viral causes can include: RSV, rhino/enterovirus, coronavirus, influenza virus, adenovirus, human metapneumovirus

52

what are 2 factors essential to the pathophysiology of otitis media

1. antecedent viral URT infection (i.e cold)
2. colonization with respiratory bacterial pathogen

inflammatory response to the virus obstructs the ISTHMUS of EUSTACHIAN TUBE--> causes negative pressure

secretions produced by the middle ear accumulate

bacteria colonizing URT access middle ear through aspiration or reflux, and grow in middle ear secretions

suppuration = acute otitis media

53

how is otitis media diagnosed in infants

nonspecific signs and symptoms

fever is 33-66%

54

how is otitis media diagnosed in children

otalgia (ear pain)
bulging of tympanic membrane
otorrhea (leak of CSF through ear structures)
hearing loss

55

complications of otitis media

tinnitus
vertigo
facial paralysis
mastoiditis
meningitis

56

Tx of otitis media

70-80% resolve on their own
if strep. pneumo--> treat with AMOXICILLIN (best coverage for S. pneumo of all oral B-lactams)

watchful waiting, pain relief

57

what is acute sinusitis

inflammation of paranasal sinuses lasting less than 4 weeks

58

which sex gets more acute sinusitis

women

59

which age group gets more acute sinusitis

45-75

60

what percent of acute sinusitis resolves on its own

70% (Abs often misused)

61

is viral or bacterial acute sinusitis more common

viral (200X)

62

which viruses cause acute sinusitis

rhinovirus
influenzavirus
parainfluenza virus

typically resolves in 7-10 days

63

what percent of acute sinusitis is bacterial

0.5-2% of viral URTI

10% related to dental disease

S. pneumo, H. influenzae, M. catarrhalis

64

why is imaging not recommended in acute sinusitis diagnosis

because it cant distinguish between bacterial and viral causes

diagnose on Hx and physical

65

when is bacterial acute sinusitis more likely (symptoms)

1. URTI symptoms last for longer than 10 days or worsen after 5-7

AND

2. nasal congestion/purulent nasal discharge with facial pain

+/-

3. fever/maxillary toothache/facial swelling

66

Tx for acute sinusitis

70% spontaneous resolution

normal saline irrigation is best option

antihistamines NOT recommended

steroids/Abs not shown to help