27 terms

Lecture 1: Upper respiratory infections

Chief complaint
sore throat
facial pressure
Facts about URIs
#1 reason days missed from work or school
#1 reason for medical office visit
Avg. adult has 2 - 3 URI's per year
Ave. child has 6 - 10 per year
The most common cause is a virus with more than 200 different viruses known to cause the common cold (Rhinovirus)
The # 2 reason Antibiotics are prescribed
Mode of transmission and seasonality
-Direct contact with person or surface and air particles
-Incubation period of 1 to 3 days.
-Most common in Fall/Winter (colder months) --> b/c people stay inside in close quarters and viruses thrive in low humidity
-inflamm of nose

1) Allergic rhinitis = seasonal allergies

2) Non allergic
-infectious (viral)
-rhinitis medicamentosa = use of nasal decongestants for more than 3 days = refractory
-vasomotor (odors, alcohol, emotional, temp changes, barometric pressure changes)

Tx the cause
-every sinusitis comes from a rhinitis
-always caused by a virus first

-Approximately 0.5 to 2 percent of colds and influenza-like illnesses are complicated by acute bacterial sinusitis in adults (bacteria started off as virus first)
-Uncomplicated viral rhinosinusitis usually resolves in seven to ten days.
-Acute bacterial sinusitis is also usually a self-limited disease, with 75 percent of cases resolving without treatment in one month
Normal flora of the sinus
-H. influenzae
-M. catarrhalis
MC sinus infected
Cause of complicated bacterial sinusitis
-blow our nose --> increases pressure --> pushes bacteria up into sinuses where it gets trapped
-pain often present in the upper teeth
T or F You tell the difference btwn bacteria and viruses on CT
-false use clinical picture

bacteria = fever for days, pain, purulent fluid
Management of sinusitis
-Limited Sinus CT (coronal only) $600 = maybe
-Vs full sinus CT $1,200 (not needed)
-Plain film of sinuses ($200) is no longer recommended
-Tylenol / Decongestant = MAIN
-phenylpropanolamine, pseudoephedrine, and phenylephrine
Treat with antibiotics if....
-symptoms persisting greater than 3 weeks is the general rule of thumb or...

-maxillary pain or tenderness in face or teeth and persistent nasal discharge without improvement after 7 days
Antibiotic of choice for bacterial sinusitis
Amoxicillin TID for 10 days
MC cause = viruses

-The peak incidence of pharyngitis occurs in the school-aged child aged 4-7 years.
-Peak incidence of GABHS is 3 to 14 year olds

-GABHS infection is rare in children younger than 3 years old

-GABHS causes approximately 15% of all adult pharyngitis cases and about 30% of pediatric cases.
Group A beta hemolytic strep untretead results in...
S. pyogenes

Untreated =
-acute rheumatic fever
-acute GN
-peritonsillar abscess
-toxic shock syndrome
T or F can tell just by looking at throat whether its bacterial or viral
Classic clinical picture for pharyngitis
fever of greater than 101.5°F
tonsillopharyngeal erythema
swollen tender anterior cervical adenopathy
elevated WBC count
palatal petechiae
absent cough or rhinorrhea
Centor Strep Throat criteria***
History of fever
Tender anterior cervical lymph nodes
Tonsillar exudates
Lack of cough

Number of symptoms Probability of Strep
0 2.5%
1 6.0 - 6.9%
2 14.1 - 16.6%
3 30.1 - 34.1%
4 55.7%
Rapid strep antigen test
rapid strep antigen tests are 93 - 95% specific
original rapid strep tests 50-70% sensitive
newer high sensitivity tests are approx 85%
newest tests are up to 97% sensitive
Blood agar throat culture is 94 - 99% sensitive

General rule of thumb is to test if 2 or 3 positive Centor criteria***
Back up culture confirmation if RSAT is negative in children only (variable for adults)****
Modified Centor score and clinical decision tree
*1 point for absence of cough, swollentender anterior cervical nodes, temp>100.4, o tonsillar exudates or swelling

*1 point if age 3-14
*0 points if 15-44
*-1 pointif >44

score of 0-1 = no further testing or Abx
1-3 = throat culture or rapid strep test (only give abx if comes back pos
>4 = treat empirically with Abx while waiting for test to come back****
How should we dx and treat strep throat
Rapid Strep Antigen Test
Throat culture if Rapid Strep is unavailable but you have high index of suspicion
Call in Antibiotic (Pen is DOC or erythomycin for 10 days***)
-Once again, like typical URI's, most are caused by viruses
-Up to 80% of patients with acute bronchitis who seek care are given antibiotics.
-Perhaps due to suspicion that the bacterial pathogens that cause pneumonia, such as Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Moraxella catarrhalis, or even gram-negative bacilli, can also cause acute bronchitis.
-but NO evidence that these pathogens cause acute bacterial bronchitis
only 2 situations where bacteria might be cause of bronchitis
-patients with mechanical airway abnormalities such as tracheostomy or endotracheal intubation
-exacerbations of chronic bronchitis
What about Mycoplasma pneumonia
-Adults with acute cough lasting for more than five days implicate M. pneumoniae in fewer than 1 percent of cases = RARE

-instead think about pertussis = severe paroxysmal cough, with or without whooping
-DOC tx = Macrolides
MC causes of chronic cough >8 weeks
Postnasal drip syndrome 41%
Asthma 24%
GERD 21%
Chronic bronchitis 5%
Bronchiectasis 4%
Miscellaneous conditions 5%.
T or F: Axithromycin is effective in treating acute bronchitis
Treatment of acute bronchitis
-Symptomatic (Vit C, maybe albuterol)
What is most important when treating someone with bronchitis
-patient education
-as long as you explain to patients that bronchitis is most likely not caused by bacteria and prescribing Abx just increasing abx they will be satisified with no prescription