Microbiology Flashcards
conjunctivitis
conjunctiva is red and inflamed
acuity, pupillary responses and corneal lustre are unaffected
eyes itch, burn and lacrimate
there may be photophobia
often bilateral with lids sticking together

papillae conjunctivitis
red dots of varying size
allergic and bacterial

follicular conjunctivitis

course of conjunctivitis
usually self-limiting
what should you consider in prolonged conjunctivitis - especially in YP or those with sexual disease
chlamydial conjunctivitis
common organisms of bacterial conjunctivitis in neonates
- Staph. aureus*
- Neisseria gonorrhoea*
- Chlamydia trachomatis*
common organisms for bacterial conjunctivitis in all other ages
- Staph. aureus*
- Strep, pneumoniae*
- H. influenzae* (especially in children)
what can allergic conjunctivitis be treated with
anti histamine drops
how does the discharge of bacterial conjunctivitis differ from viral etc
more purulent and eye more red

what is the first line treatment for bacterial conjunctivitis
swab of eye and treat with topical ABx, usualyl chloramphenicol
2nd and 3rd line treatment for bacterial conjunctivitis
2 - fusidic acid (S. Aureus)
3 - gentamicin (Gram-negatives, severe but good)
what organism does chloramphenicol not treat
Pseudomonas aeruginosa
when should chloramphenicol be avoided
anaplastic anaemia (possible association) or allergy
describe the defining features of viral conjunctivitis
more pink than bacterial
there is no green/yellow pus, more of a thick watery secretion
there is often a history of URTI, and pre-oricular and submandibular lymph nodes often are enlarged
very contagious
red velvety appearance of conjunctiva and raised follicles

what is the most common cause of viral conjunctivitis
Adenovirus
adenovirus conjunctivitis
often follows URTI
small lymphoid aggregates appears as follicles on conjunctiva
HSV conjunctivitis
usually a manifestation of primary infection
treated with acyclovir (analogue of guanosine)

ophthalmic shingles
can present with purulent conjunctivitis etc
pain and neuralgia in the distribution of CNV1 dermatome precedes blistering rash
Hutchison’s sign may be present - tip of nose from nasociliary branch

chlamydial conjunctivitis history
unresponsive to treatments
chronic and may last for months
who usually gets chalmydial conjunctivitis
more common in newborns
also young adults
symptoms of chlamydial conjunctivitis
unilateral conjunctivitis (less commonly bilateral)
chronic history
there may be symptoms of urethritis and vaginitis
describe the eye in chlamydial conjunctivitis
it is a chronic follicular conjunctivitis
the follicles are described as being like rice grains, can lead to subtarsal scarring

treatment of chlamydial conjunctivitis
topical oxytetracycline
oral azithromycin may also be needed for genital chlamydial infection
keratitis
Corneal inflammation, identified by a white area on the cornea indicating a collection of white cells.







