Otitis media, Otitis externa - PowerPoint Presentation

Slide1

Otitis media, Otitis externa , and Eye diseases:

Otitis media

:

is the inflammation of the area between Eardrum (Tympanic membrane) and the inner ear; including Eustachian tube.

-Infections of

air-filled cavities

of the head occur when

normal drainage routes become obstructed

.

-Infection of air-filled cavities of the head results in:

1-Otitis media.

2-Sinusitis.

3-Mastoiditis.

Slide2

N

-Because the cavity of the middle ear is contiguous with the

mastoid air cells(spaces of temporal bone); individuals with acute otitis media also have mastoiditis.

Slide3

N

-

The majority of cases

occur in children between 6 and 36 months of age.-Children are susceptible to otitis media for several

reasons:

1-The

medial orifice

of the

eustachian tube

is

more open

in

infancy than later in life.

2-

Milk

feeding

(giving a bottle at bedtime) results in

reflux

of

pharyngeal contents

into the

lumen

of

eustachian

tube

.

3-

Eustachian

tube

is

shorter

and more

horizontal

in young

children.

4-The viral infection of upper respiratory tract and

lymphoid

tissue

results in

eustachian tube obstruction

.

Slide4

Pathogenesis:

-

Inflammation

of upper respiratory tracts due to: 1-Viral infections; influenza A or B, and adenovirus. 2-Allergy

(Rhinitis).

-Swelling of lymphoid tissue

(Eustachian tonsil)

around

eustachian

tube.

-

Eustachian tube obstruction

.

-Absorption of air of middle ear slowly by surrounding

tissues.

-

Creation of negative pressure

(vacuum) in the middle ear.

-

Accumulation of fluids

; so

normal flora

of upper

respiratory tract could

invade middle ear space

.

Slide5

N

-

Colonization

of middle ear cavity lining epithelium.-If the microbe has a polysaccharide

capsule

:

-

P

olyclonal

lymphocyte

activator

; cytokines production;

chemotaxis

of immune cells and

inflammation

.

-Conductive hearing loss.

-If the infection is not treated; otitis media and mastoiditis

could be complicated by:

1-

Facial

nerve paralysis

.

2-

Infection of peripheral nerves; results in

deeper

brain

abscess

.

Slide6

N

3-

Infection of veins that bridge

surrounding bony structures and the cerebral cortex; septic thrombophlebitis) results in subdural empyema (in some cases;

related to

epidural

abscesses

).

Acute abscess

is frequently caused by a

mixed bacterial flora

c

onsisting of

obligate and facultative anaerobic bacteria

;

similar

to the

mixture of microbes

infecting middle ear, mastoid, and sinuses.

Slide7

N

Treatment of poly-microbial brain abscesses:

Antibiotic combination:

1-Vancomycin or Ceftriaxone: to cover Staphylococci and

other

Gram positive

beta-lactamase producers.

2-

Metronidazole

: to cover

anaerobic bacteria

.

3-

Quinolones

or

Macrolides

working effectively at acidic

pH.

Slide8

The Normal flora of upper respiratory tracts:

-

Streptococcus

pneumoniae (Nasopharynx).-Haemophilus influenzae

(non-type b) (Nasopharynx).

-

Moraxella

catarrhalis

(Nasopharynx).

-

Staphylococcus aureus

.

-Coagulase negative

Staphylococcus

species.

-

Diphtheroids

species.

-

Neisseriae

species.

-

Candida

species.

Slide9

Causes of Otitis media:

1-

Streptococcus

pneumoniae (the most common cause).2-Non-typeable Haemophilus influenzae

.

(the second common cause).

-Both

Strep.

p

neumoniae

and

H.

influenzae

causes

80%

of

otitis media cases

.

3-

Moraxella

catarrhalis

.

-Gram’s negative non-motile

coccobacilli

in pairs.

-Aerobic fastidious oxidase positive bacteria.

4-Other normal flora of upper respiratory tracts(rare).

Slide10

Clinical Classification of Otitis media:

1-Acute suppurative:

-Pus accumulated in middle ear; mainly in infant and children.

2-Chronic:

A-Recurrent OM due to other causes.

B-Secretory OM : Very common persisting middle ear

effusion

after OM in

40% of cases

.

(

Thick fluid consistency

).

Management:

1-Amoxicillin or Ceftriaxone.

2-Amoxicillin/

Clavulanate

for

B

eta-Lactamases strains

.

Slide11

Otitis Externa :

Otitis Externa

: is an inflammation of the outer ear and ear canal.

-It is mainly caused by bacterial or fungal agents.-Otitis externa could be established due to:

1-Swimming in polluted water (germs contamination).

2-Impairment in the integrity of the skin (dermatitis).

-Hospital acquired otitis

externa

could be caused by

hospital dwelling bacteria as a post-surgical infection.

Slide12

Causes of Otitis Externa:

Exogenous:

-

Pseudomonas aeruginosa (the most common cause).

Endogenous:

Normal flora of outer ear canal

:

-Coagulase negative

Staphylococci

.

-

Staphylococcus aureus

.

-Gram negative bacilli

.

-Fungi:

Candida species. Malassezia furfur.

Slide13

Clinical classification of Otitis Externa:

1-Acute localized secondary to folliculitis:

-Painful pustule with local lymph node enlargement; Staphylococcus aureus.2-Acute diffuse (Swimmer’s ear):

-

Pseudomonas aeruginosa

.

-Itchy, painful, edematous, reddened OE with purulent

discharge.

3-Chronic OE secondary to chronic otitis media.

-Fungi, Candida plus other chronic disease

(Immunocompromised Pat. ).

Slide14

N

4-Malignant OE

(

Necrotizing OE) Secondary to diabetic microangiopathy; Pseudomonas spp

.

-Serious infection.

-Not-malignant (Non-Cancerous).

-Malignant in its progressive, fatal course.

-Spreading of infection to surrounding bone, blood

vessels, facial nerve and meninges.

-

Complicated by

inflammation of cranial nerves

and their

branches ;

facial

(7th) nerve paralysis. -It is associated with

immunocompromised

patients

.

-Diagnosis: Full investigations: CT Scan, MRI.

Slide15

N

Management:

1-Acute

: As OM.2-Acute diffuse: Local Neomycin, Polymyxin.3-Chronic

:

Local imidazole for fungi and treatment of OM.

4-Malignant OE

: I.V Tobramycin and

Ceftazidime

(weeks)

With surgery.

Diagnosis:

Clinical specimen

:

Ear Swab (cotton swab).

Slide16

N

Culture:

on Enriched media.

-Blood agar incubated under aerobic conditions. -Chocolate agar: incubated under anaerobic conditions.Isolation of Pseudomonas species:-Encapsulated, motile, Gram negative bacilli.

-Oxidase

positive

,

Exopigments

production.

-Antibiotic resistance

strains.

(

greenish

yellowish

exopigment

production; pyoverdin).

Slide17

N

Isolation of

Staphylococci

:Staphylococcus aureus:Gram positive cocci, coagulase positive, novobiocin sensitive, and Mannitol fermenters.

Other

Staphylococci

:

Gram positive

cocci

, coagulase negative,

novobiocin

resistance.

Novobiocin

sensitivity Mannitol fermentation.

Slide18

Infectious diseases of the Eye:

Keratitis

:

inflammation of transparent eye’s cornea; the anterior part of the eye (covers

the

iris, and pupil).

Causes

:

1-Amoebic keratitis

:

a serious corneal infection usually affecting contact lens

wearers.

Etiology

:

Acanthamoeba

.

2-Bacterial keratitis

:

Due to injury of wearing

contact lenses.

Etiology: Staphylococcus aureus, &Pseudomonas species.

Slide19

N

Staphylococcus aureus

is a major cause of infections of the eyelid and cornea.

Staphylococcus aureus can infect the glands of the eyelid; resulting in the production of a sty.

Sty

is a painful red swelling

on the margin of the eyelid.

Treatment

:

bacitracin ointment.

Slide20

N

3-Fungal keratitis:

Keratomycosis

: Etiology: Fusarium species. -Infection

is established due to corneal injury

in agriculture workers or

immunocompromised

patients.

Fusarium

Chlamydospores

.

Fusarium

Macroconidia

.

Slide21

N

4-Viral Keratitis:

Etiology: Herpes simplex virus types 1 and 2.

Diseases

:

A-Primary infectious keratitis:

Vesicular eruption

of the eyelid, infection of cornea

leading to

corneal ulcers

.

B-Recurrent herpes keratitis:

-(More common than primary

keratitis).

-In immunocompromised patients. -Mild irritation and photophobia.

Slide22

N

5-Onchocercal Keratitis:

Onchocerciasis

: -Parasitic infection of the eye’s cornea (Corneal lesions). -Etiology: Onchocerca

volvulus

.

-Transmitted by the bite

of blackfly

.

-

Disease

:

African River blindness

.

Slide23

nChemotherapy for Keratitis and Corneal Ulcers:

1-Bacterial Keratitis:

Local broad-spectrum antibiotics; Vancomycin and tobramycin.2-Viral keratitis: Acyclovir.

3-Fungal Keratitis:

Amphotericin B.

4-Amoebic keratitis:

Propamidine

drops plus oral ketoconazole.

Slide24

Conjunctivitis:

Conjunctiva: is a thin, translucent, mucous membrane that lines the eyelid and covers the white portion of the eyeball.

Conjunctivitis is divided according to etiology into:

A-Bacterial conjunctivitis: -Redness, swelling of the eyelid, and

muco

-purulent discharge

.

- Yellowish-greyish discharge:

pyogenic

cocci

infection.

-

Treatment:

Local bacitracin

or neomycin.

Slide25

N

Types of bacterial conjunctivitis:

1-Trachoma: Etiology:

Chlamydia trachomatis:Serotypes A, B, Ba, and

C

causes chronic

keratoconjunctivitis

(

Trachoma

) that results in

blindness

.

Trachoma is a leading cause of blindness in endemic areas of northern India, the Middle East, and North Africa.

Transmission:

-Personal contact ; eye-to-eye via droplets by

contaminated

hands (transfer of elementary bodies).

Chemotherapy:

Oral azithromycin or tetracycline.

Slide26

N

Chlamydia

trachomatis:-Unicellular obligatory intracellular bacteria that has rigid cell wall. -Infective stage: The elementary body.

-

Inclusion

bodies (Trachoma) infected

conjunctival

epithelial cells

(Reticulate body: diagnostic stage).

Slide27

N

2-Ophthalmia

neonatorum

: Etiology:1-Neisseria gonorrhoeae:

-The most severe cause of

hyperacute

bacterial

conjunctivitis of newborn.

-It is acquired during passage of newborn through the

birth canal of a mother infected by gonococci.

-

Neisseria

species are

Gram

negative oxidase positive

diplococci

that ferment glucose only.

Slide28

N

2-

Chlamydia

trachomatis:(Ophthalmia neonatorum):

-This type of newborn conjunctivitis is associated with

serotypes

D-K

.

- 50% of Infants born with infection due to passage

through the

birth canal.

-

inclusion conjunctivitis heals without eye damage

-

Treatment of both types 1 and 2

:

(

Prophylactic drug

):

Erythromycin ointment; most strains of Neisseria

gonorrhoeae

are

Beta-Lactam

resistant

.

Slide29

N

B-Viral Conjunctivitis

:(Pink Eye):

diffuse pinkness of Conjunctiva. -Adenovirus infection is the most common cause of viral conjunctivitis.

-

Acute conjunctivitis

, and

pharyngoconjunctival

fever

.

-A more serious infection is

epidemic

keratoconjunctivitis

,

which involves

formation

of a

painful ulcer

of the

corneal epithelium

. Electron microscopy: Double-Stranded DNA, Icosahedral

naked virus.

Slide30

N

-

Herpes simplex virus

cause serious Herpetic keratoconjunctivitis, which requires treatment with acyclovir.

-

Acute hemorrhagic conjunctivitis

is a highly

contagious disease caused by:

1-Enterovirus 70

.

2-Coxsackievirus A

24

.

Viral hemorrhagic

Conjunctivitis

due to Enterovirus-70

infection.

Slide31

Diagnosis of Eye infection:

Clinical specimens:

1-Eye cotton Swab.

2-Conjunctival Scraping. 1-Direct microscopy: A-Swab

for Microbiology (

Gram’s stain

):

detection of

G+ve

and

G-

ve

bacteria

, and

yeast

.

B-

Conjunctival

scrapes

for cytology lab:

detection of Chlamydia diagnostic stage. C-Conjunctival Scrapes for immunohistochemistry:

detection of

viral infections

or

Chlamydia

infection

.

Slide32

N

2-Detection of viral genetic material and

Chlamydia

genetic material by molecular methods: 1-Nucleic acid DNA hybridization.(Probe hybridization). 2-PCR :

Primer amplification of genetic material.

3-Cultivation of bacterial agents:

-Eye swab should be inoculated on Enriched media.

-

Blood agar

and

Chocolate agar

should be incubated

under

aerobic

and

anaerobic

conditions

respectively

.

Clinical significance

: isolation of pyogenic cocci and Neisseria gonorrhoeae

.

Slide33

Detection of Virus and Chlamydia genetic materials by

Immunofluorescent

Microscopy:

Detection of viral antigen by Localization of specific Adenovirus-

monoclonal antibodies.

Coxsackievirus

receptor on Epithelial cells of conjunctiva.