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
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
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
keratitis
Corneal inflammation, identified by a white area on the cornea indicating a collection of white cells.
hypopyon
a collection of inflammatory cells seen in the anterior chamber, also called sterile pus
HSV keratitis
classical dendritic ulcer as this is where the infection is
very painful and may be recurrent
DO NOT treat with steroids - acyclovir
adenovirus keratitis
bilateral and usually follows UTI
contagious
may affect vision
small white flecks are seen - subepithelial infiltrates
fungal keratitis
usually seen in contact lense wearers
common organisms are: acanthamoeba and pseudomonas aeruginosa
there is typically more of a chronic indolent history, often with note of trauma from vegetation
less of a red eye is seen
orbital cellulitis
inflammation of the eye tissues behind the orbital septum, sight threatening
it is important to distinguish from pre-septal cellulitis as this is not that severe
typical patient with orbital cellulitis
Typically children with lid swelling, fever, orbital inflammation, and decreased eye mobility
what is the most common organism causing endophthalmitis
Staph epidermidis
