Prunuske -- Conjunctivitis Flashcards Preview

Neuro Block 3 > Prunuske -- Conjunctivitis > Flashcards

Flashcards in Prunuske -- Conjunctivitis Deck (31):
1

Blepharitis

eye lid infections

2

Conjunctivitis

conjunctiva- thin membrane infection

 

3

Kerititis

cornea infection

vision defects, photophobia, pain (cornea has lots of nerve endings), and foreign body sensation

Viral keratitis is caused by HSV-1, adenovirus, and VZV.
Bacterial keratitis Staph. aureus and epidermidis, Pseudomonas aerugrinosa, and Bacillus cereus.

Treatment- for bacteria Moxifloxacin eye drops
                          for HSV-1 trifluridine + acyclovir 

4

Keratoconjunctivitis

conjunctiva and cornea infection

 

5

Uveitis

iris, ciliary body, and choroid infection

 

6

Chorioretinitis

choroid and retinal layers infection

Blood borne route via retinal arteries, frequently manifestation of systemic disease

Congenital Toxoplasma (parasite) and CMV (ganciclovir implant) are most common especially in HIV and neonates

 

7

Endophthalmitis

aqueous and vitreous humor

8

tears contain what?

Secretory IgA is a dimer
Secretory piece protects IgA from being degraded

 

9

most common cause of conjunctivitis

adenovirus

(also alergies, chemical exposure)

10

bacterial vs. viral vs. allergic conjunctivitis

bilateral (bacterial: 50-75%; viral; 35%, A = mostly)

discharge (bacterial: macopurulent; viral: watery)

MUST ADD MORE

11

Allergic rhinoconjunctivitis (hay fever)

antigen --> b-cell --> IgE --> IgE binds mast cell --> subsequent exposure --> histamine release from mast cell. 

Management
Antihistamines, mast cell stabilizers, nonsteroidal anti-inflammatory drugs
Avoid antigen and glucocorticoid
Steroids effective but can cause complications like glaucoma, cataract, and 2ndary infections 

12

Viral conjunctivitis

Neonatal = ?

Post-natal = ?

HSV-1

Adenovirus

 

13

Adenovirus

non-enveloped, double-stranded DNA virus

Lytic in epithelial cells and latent in lymphoid

highly contagious spread through fomites like swimming pools

Adenovirus infects epithelial cells of respiratory tract (4,7), conjunctiva (invasive 19,37), and
enteric organs (40,41,42).  What determines this specificity? ... coxsackie adenovirus receptors

14

Acute bacterial conjunctivitis (mucopurulent)

Children- Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, Moraxella

Adults- Staphylococcus aureus, Strep. Pneumonia, Escherichia coli,    Pseudomonas aeruginosa, Moraxella
 

Empiric treatment with both Gram positive and negative coverage: Moxifloxacin solution (fluroquinolone) (best coverage, expensive, >3  yr) 

15

What is the mechanism of action for moxifloxacin, trimethoprim, and polymyxin B?

moxifloxacin: binds DNA gyrase (TOPO II)

trimethoprim: binds to DHFR 

polymyxin B: binds phosphitidal ethanolamine and creates holes in outer membrane

16

Hyperacute bacterial conjunctivitis

Neisseria gonorrhoeae 

Copious yellow-green discharge (purulent)
Preauricular adenopathy

Gram stain for gram-negative intracellular diplococci and growth on chocolate agar supplemented with vancomycin, colistin, nystatin, and trimethoprim (nonsterile site)

Treat promptly with systemic ceftriaxone

17

Ophthalmia neonatorum

conjunctivitis or keratoconjunctivitis  occurring within first four weeks of birth

(N. gonorrhoeae, C. trachomatis, Staphylococcus, Streptococcus, E. coli, H. influenzae or H. simplex)

Prophylaxis with erythromycin ointment 

18

erythromycin, azithromycin

macrolides

Inhibits translation by binding 23S rRNA of the 50S subunit

Spectrum: Broad coverage of respiratory pathogens, Chlamydia

Resistance: Increased efflux, hydrolysis of drug by esterases, methylation of drug binding site

Adverse effects
GI discomfort, Hepatic failure, and Prolonged QT interval

19

Inclusion conjunctivitis  (serotypes D-K) 

Trachoma (serotypes A-C)

Chlamydia trachomatis 

Trachoma = leading cause of blindness worldwide 

Treate with azithromycin

20

Chlamydia trachomatis

life cycle

Elementary body (EB) enters epithelial cells, converts to reticulate body (RB), and then replicates using binary fission

elementary body has ridgid outer body

21

Chronic conjunctivitis is associated with....

Blepharitis:  Inflammatory disease of the eyelid margin where too much oil is produced

Stye- external localized inflammation often on lower lid due to bacterial growth in eyelash follicle, if forms inside or under eyelid called hordeolum
Chalazion- (lipogranulomas)”small lump” plugging of the meibomian gland

Treatment:  Keep lid clean. Warm compress or massage to open gland. Erythromycin ointment.

22

keratoconjunctivitis with HSV-1

Similar presentation to adenovirus although lesions can be painful especially if scarring of the cornea occurs and often only one eye

Avoid corticosteroids since can facilitate corneal penetration

If corneal involvement treat with topical trifluridine and systemic acyclovir and consider prophylactic treatment with erythromycin to prevent bacterial superinfection

23

acyclovir and ganciclovir are prodrugs

Inhibits viral DNA synthesis by acting as a competitive substrate for viral DNA polymerase and lead to chain termination

requires thymidine kinase (?)

24

Trifluridine 

pyrimidine analog effective against acyclovir resistant virus because it can be phosphorylated by host kinases also making it much more toxic and should only be used topically

25

Pseudomonas aeroginsoa

Gram negative, aerobic rod, flagella

26

Q image thumb

CMV retinitis begins at periphery and can spread like “brushfire”

A type of Chorioretinitis- blurred vision and visual field defects

27

Viral conjunctivitis epidemics are often caused by ...

adenovirus

28

Treat neonates prophylactically with ...

erythromycin to decrease opthalmia neonatorum

29

Blepharitis is often associated with ...

conjunctivitis

30

Chorioretinitis is usually linked to ...

systemic disease (CMV and HIV)

31

Interior eye infections like endopthalmitis may be transmitted through ....

blood or introduced during surgery.