Exam 4: Ear Infections

Question 1

What are the common etiologic agents of acute otitis media?

Answer 1

Strep pneumoniae, H. influenzae (non-typable), Moraxella catarrhalis, Viral (RSV, rhinovirus)

Question 2

What are the characteristics of Strep pneumoniae?

Answer 2

Gram positive, diplococci (lancet shaped)

Question 3

What can increase susceptibility to otitis media

Answer 3

chronic diseases: alcoholism, DM, chronic renal diseases

Question 4

How is S. pneumoniae drug resistant?

Answer 4

Changes in the penicillin binding protein

Question 5

What are virulence factors of S. pneumoniae

Answer 5

Capsule- blocks phagocytosis by interfering with complement, Choline binding proteins alters vascular permeability, Hydrogen peroxide- damage host cells and bactericidal, Neuraminidases- cleave host mucins, Pneumolysin- pore forming toxin, Iron acquisition proteins

Question 6

What are the characteristic of H. influenze

Answer 6

gram-negative pleomorphic coccobacillus, anaerobic

Question 7

How do you grow H. influenzae?

Answer 7

requires additional blood factors like NAD and hematin on chocolate agar

Question 8

What is the penicillin resistance of H. influenzae?

Answer 8

Beta lactamases

Question 9

What are characteristics of Moraxella catarrhalis

Answer 9

Gram-negative, aerobic, diplococcus, oxidase-positive, nonmotile, fastidious (chocolate agar), pili

Question 10

What is the penicillin resistance in M. catarrhalis?

Answer 10

Produce beta lactamases

Question 11

What are prevention strategies of acute otitis media?

Answer 11

Avoid cigarette smoke and sick children, breastfeed and avoid bottles before bed, wash hands frequently, stay up to date on vaccines

Question 12

What is the recommended empiric treatment in 6 month-24 month olds? What does it cover?

Answer 12

Oral amoxicillin (provides coverage for Strep pneumoniae, H. influenzae)

Question 13

If the patient to empiric treatment with amoxicillin, what should be added to the treatment?

Answer 13

Amoxicillin with clavulanate

Question 14

What else can be prescribed, besides amoxicillin and clavulanate, to deal with a patient’s otitis media symptoms

Answer 14

Pain management (acetaminophen and ibuprofen) and decongestants

Question 15

What is a good treatment for recurrent ear infections in children?

Answer 15

Ear tube insertion for recurrent infections

Question 16

What are complications of otitis media?

Answer 16

Conductive hearing loss/delayed speech due to TM perforations, Cholesteatoma, Infection spreading to mastoid, inner ear, temporal bone and meninges

Question 17

What is otitis externa also called?

Answer 17

Swimmer’s ear

Question 18

What are risk factors for otitis media?

Answer 18

maceration- trauma, foreign bodies, excessive swimming, middle ear infxns, diabetes

Question 19

What is the bodies natural defense to otitis media?

Answer 19

ear wax contains lysozymes and is slightly acidic to prevent microbial growth

Question 20

What is the common etiology of acute localized otitis externa? Symptoms?

Answer 20

Staphylococcus; pustule or furuncle associated with hair follicles

Question 21

What is the etiology of acute diffuse otitis externa? Symptoms?

Answer 21

Pseudomonas aeruginosa; itches, red ear canal, painful

Question 22

What is the etiology of malignant otitis externa? Symptoms?

Answer 22

Pseudomonas aeruginosa; invasion of adjacent bone and cartilage which can progress to cranial nerve palsy and death

Question 23

What populations is malignant otitis externa prevalent in?

Answer 23

Elderly, poorly controlled diabetes, immunocompromised

Question 24

What are the fungal etiologies of otitis externa?

Answer 24

Aspergillus, Candida albicans

Question 25

What is the management of otitis externa?

Answer 25

Cleansing with low pH topical solutions, don’t flush unless TM is intact, treat with analgesics (NSAIDs, acetaminophen), Topical antibiotics (unless cellulitis or fungal)- Ciprofloxacin + steroid, Neomycin + polymyxin + hydrocortisone

Question 26

What is the bacterial cause of a patient who has green-yellow discharge from the eyes?

Answer 26

N. gonorrheae

Question 27

What is the cause of patients with red, mild cold and clear drainage of the eyes?

Answer 27

Adenovirus

Question 28

What is the cause of patients with visual field deficits, most commonly in HIV-infected individuals

Answer 28

CMV

Question 29

What bacteria releases pneumolysin, a pore forming toxin?

Answer 29

S. pneumoniae