EYE infections Flashcards
conjuntiva NF orgs
Staph epidermis, diphtheroids, Propionibacterium acnes
cause of conj. inflamm
chem irritants, allergies, inf. agents, diminution of tears, (keratoconj. sicca)
host defense mechs against conjunct.
mech. action of blinking
tears: lysozyme, sec. IgA, host-der. antimicrobial peps, etc
conj. : lympos, plasma cells, neutros, mast cells
int. eye protected by eyelids, conj., sclera, cornea (sterol and imm. privileged)
trauma or disease cause inflammation
(papillae, follicles present)
extravasation of neutros, macros, lymphos from conj. vasc into tears
follicles are..
focal lymp. aggr. assoc. w. viral/chlamydial infection (1-2mm) translucent elevations on lower conjunctiva
papillae are..
mult. minute, opaque elevations on conjunctiva, non-specific but typ. assoc w/ EC bac disease
conjun. (bac and viral) s/s
itching, burning, discharge, preauricular lymphaden. +/-, typ. unilat, most cases benign, self-limiting
conj. discharge
serour fluid OR purulent (PMN or moncytic) OR mucopuruleng (exc. PMN) (PMS: bac, Monocytes: viral/fungal)
-if discharge, clears w/ blinking
conj. complications
medical emergency req. imm. tx bc indicated inf. has spread to cornea (keratitis): vision impairment has begun
symp. of keratitis
eye pain, photophobia, vis. impairment
ddx conjunc.
conjunctivokeratitis, blepharitis, corneal abrasion, FB, other cause of subconjunc hemorrhage (cough/V), iritis, glaucoma, chem burn, scleritis
bac conjunc (acute purulent/mucopurulent) conj. most common orgs
*Staphylococcus aureus (G+ cocci)
*Streptococci (G+cocci) S. pneumoniae, S. pyogenes (Staph & Strep most common in adults/ww)
H. flu (giogroup aegyptius (G- rod)
Moraxella catarrhalis (G- cocci)
Neisseria gonorrhoeae and Chlamydia spp.
bac conj. common orgs for age group
neonates: GC, chlamydia
up to school age: 2x more likely bac>virus
>=school age: viral/allergic (20%: adenovirus) epidemic keratoconjunc. more common in adolescents, adults
pink eye
acute contagious conjunct. w/ sub conj. hemorrhage (pink sclera)
most common: NTHi (aegyptius), Streptococcus pneumoniae (less moraxella spp., Pseudomonas aeruginosa)
*most common form of conj. in children
symps: gen conj. s/s, rapid, unilat lid edema, poss. contralat inv. 1-2 days, purulent neutro discharge, lid margin crusting, subconj hemorrhage (pink sclera), abs. of pre auricular lymphaden.
conjunc.-OM syndrome
orgs: NTHi, S. pneumo, Moraxella catarrhalis
infants, young kids (spreads btw siblings)
conjunc-OM dx
clin. obsv. lab confim: conjunc swab–>smear–>Gs, Cx, Abx sens. testing
conjunc-OM tx
benign and self-lim: 10-14 d, *EXCEPT S. aureus origin
topical abx w/ br-spec abx for 7-10 days: trimethoprim-polymixin, fluoroquinolone
*milder inf. will resolve w/out tx
Infectious Hyperacute Mucopurulent Conjunctivitis is called this in the neonate
Ophthalmia neonatorum (1st 28 days) contam of eyes thru birth canal
IHM conjun org: Neisseria gonorrhoeae
(G- cocci), major cause of STD, affects 50% of all infants born to gon-inf. moms, earlier (d 2-5 of life) than C. trachomatis
rapid, fulminante progression w. copious mucopurulent exudate, erythema, eyelid/conjunc edema, freq. bilat
rapidly destr. inf–>ulc, perf, blindness even in abs. of any corneal trauma/abrasio
inf. hyperacute mucopur. conjunc. (N. gon) tx
- Medical emergency!* imm. tx and consult w. ophthalmologist (unlike Chlamydial ophthalmia neonatorum: tx but not emerg.)
- tx imm. s. syst. abx (ceftriaxone or other 3rd gen cephs/fluoroquinolones (ciprofloxacin), freq. saline eyewash w/ abx, delayed tx (even1-2 d) can result in blindness!
inf. hypacute mucpur conjunc (Chlamydia trachomatis) (serotypes D-K)
Inclusion conjunct of newborn, G- cell wall architecture (can’t see w. Gs), an obli. IC pathogen
- affects many infants born to moms inf. w/ chlamydial cervicitis
- appears later: day 5-10 of life
- less purulent, more serous discharge, less progressive
- sight not threatened and dis. is self-limiting
IHM conjunc (C. trachomatis) tx
oral and topical erythromycin
Herpes classic triad (conjunc)
skin, eye, mouth (SEM): inclusion keratoconjunctivitis of newborn
obl. IC pathogen: HHV-2, affects some infants born to inf./shedding moms
appears even later! 9-10d of life) than N. ton and C. trach ocular disease
tx: acyclovir or other antiviral
other causes of inf hypacute mucpur conjunc
vag flora: Staph, Strep, some G- rods
symptoms of bacterial inf. IHM conjunc
unilat or bilate erythema, sev. eyelid edema, conjunc. edema, profuse exudate w. marked purulence
Inf. hypacute mucopurulent conjunc dx
s/s, start emp. tx imm, Gs, Giemsa stain, DFA stain, Cx from conjunctival scrapings or swabs (also from mom)
Gs and Cx + for N. gonorrhoeae reveal
G- diplococci w/in cytoplasm of PMNs on Gs of conjunct. on smears and scrapings from symp. child
*if negative, may indicate chlamydial etiol. (not routinely Cs in labs, not vis. on Gs)
Giemsa or DFA stain of conjunc material that reveal intracytoplasmic inclusions is positive for
chlamydia (also if chlamydia Ag present)
IHM conjunc. can have coinfection w/
N. gon and C. trach (50% of inf. women)
prev. of ophthalmia neonatorum
Crede procedure: silver nitrate (1%) for N. gon + abx eye drops (eryth, doxy, tetra for both G/C) –>causes chem conjunct. 24-48 hrs, prev. blindness
Inclusion conjunctivitis (IC)
any conjunct. caused by ob IC pathogen
-presence of IC (cyto or nuc) inclusions which is a cytopathic effect induced by the pathogen
IC etiol.
ob IC pathogen: Chlamydia trachomatitis or any viral conjunc. agent
IC patho
lysis and/or necrosis of epi cells–>inflamm resp. (symptoms)
typ. follicular–>cause irritation and FB sensation
dx: (cytoplasmic inclusions obs. on microscopic findings. of conjunct scrapings, or on Giemsa stains, DFA/FAT for chlamydia
if viral: IN inclusions on Tzanck stained scrapings/smears for herpes virus)
Chlamydia trachomatis(G-) conjunctivitis
causes IC at any age–>end stage in adult is trachoma (*leading cause of prev. inf. blindness ww)
trachoma
keratoconjunctivitis which may result in partial/total vision loss
trachoma org.
C. trachomatis (serovars A thru C)
trachoma incidence
poverty/unsanitary: underdev. nations: Mid East, SE Asia, Africa, SW US (immig. pops and indian reserv)
not transmissible h to h, but by low sanitation (lack of clean H2O); via flies, fomites, finger-eye inoculation
*inf. kids are source/reservoir
incidence of active dis. dec w/ age
trachoma immunology
“double-edged sword” limits replication of pathogen & induces patho changes to eye
some protect. immun. (dis. of childhood, only adults have scarring)
trachoma disease course
slowww (years); begins as acute inclusion conjunct., rep. exposure to Chlamydial Ags–>intense chr. inflamm. resp–>scarring of inner eyelid–>retraction of tarsal plate–>inverting the eyelid: entropion–>inverted eyelashes (trichaisis) constantly abrade cornea–>corneal opacity/scarring
trachoma dx
clin. obs in endemic area
Giemsa, FAT: IC inclusions, low sens.
PCR is most sens., rarely done
trachoma tx/pxx
no vaccine! WHO imp. SAFE strategy: Surgery Abx Face/hand washing Environ. change (inc. clean water, better sanitation, education)
viral conjunctivitis (epidemic, inclusion conjunc)
adenovirus
coxsackie virus/ enterovirus
HSV 1, VZV, measles virus
viral conjunc. incidence
more common than bac! highly inf.–>via ocular sec. eye-hand-eye
- adenovirus most common
- prim. HSV-1 most common viral IC in kids
viral IC patho/s/s
transient, self-lim
gen symps of conjunct. w/ mild tearing/itching
thin watery discharge/exudate bearing monocytes (NOT purulent), + follicles, pre auricular lymphaden.
viral IC: pharyngeal conjunctival fever
transient, self-lim (2-4 wks)
adenovirus (3,4,7)
contam. swimming pools! so kids, y. aduls in summer (or lakes/ponds)
-kids contagious 1st 2 w
pharyngeal conjunctival fever triad
fever, pharyngitis, IC symps
pharyngeal conj. fever dx, tx, ppx
clin obs. epid. consider
no tx, resolves about 2 wks
ppx: contagious 1st 2 wks so keep out of school
epidemic Keratoconjunctivitis (“shipyard eye”)
adenovirus (8,19,37,11)
highly contagious, spread by close contact, sec. fomites
epidemic Keratoconjunctivitis symps
PCF + mild irritaiton and sev. photophob. (10-14 d post onset), painful cent. located corneal ulcer (keratoconj. from imm. resp. to inf.) may persist for mos.
epidemic Keratoconjunctivitis dx tx ppx
dx: clin obs, contact w/ case
tx: supportive/palliative, rem. of membranes and pseudo mem along w/ top steroids (imp. comfort)
ppx: isolate inf. pt (10-14 d) educate
acute epidemic hemorrhagic conjunctivitis (AEHC)
highly contagious, self-lim,
crowding, poor hygiene
acute epidemic hemorrhagic conjunctivitis viruses
Coxsackie virus (A24)
enterovirus 70
adenovirus (11)
symps of AEHC
bilat, sudden, photophob, exc. tearing (epiphora), eye irritiation/FB sens, eyelid edema, erythema, conj. hem, pink sclera, sm. superfic. corneal ulcers, superfic. punctate keratitis
short (4-5d) duration, spont. resolution
tx, ppx of viral IC (all)
tx symptomatically, topical corticosteriods, NO topical abx unless discharge becomes purulent/mucopurulent (second. bac inf)
ppx: know infectious period, keep home, approp. personal hygiene
Keratitis (corneal inflammation)
corneal inflammation–>corneal ulceration w/in 24 hours! eye emergency–>risk of rapid vision loss
keratitis bac
Staph (G+coc) Strep (G+coc) Listeria (G+rod) Neisseria (G-coc) anaerobes, GNRs, Pseudomonas aeruginosa (causes corneal inf. w/ soft contact lens use
fungal etiol. of keratitis
less common, but happens w/ eye trauma
protozoan etiol of keratitis
Amoeba: Acanthamoeba sp. (rare: tap water use for contacts)
viral etiol. of keratitis
typ. adults
immune suppression is key prec. factor, recur. common
-HSV-1: leading cause blindness in dev./industr. countries (vs C. trach in underdev. countries)
-50-500k cases in US/yr, 1000s corneal trans.
-VZV keratitis involves a periorbital lesion
tx (both HSV-1 and VZV keratitis) w/ prol. combo topical acyclovir and corticosteroids
keratitis path for non-viral agents
brkdwn in corneal epi–>invasion of corneal stroma by WBC (immpath) and bac (toxin-prod, i.e. proteases)–>some corneal scarring/opacification from inflamm. (even if tx)
keratitis path for viruses
viral repl–>cytolysis of corneal cells (dendritic figures: clinical sign)
-inf. is reactiv. of latent inf. so no breach in corneal epi layer req (virus inf. acq. early in life, remains latent in trigeminal/cervical ganglia–>triggered by environ. or sec. imm supprs–>migrates to cornea, can be shed (even when no symps)
symps of keratitis
unilat red eye, mod-sec ocular pain, photophob, serous discharge, dec. vision, loss of corneal luster/appearance, viral agents cause dendritic bodies/lesions (fluorescein dye, slit lamp)
VZV keratitis: if involves periorbital skin, many dev. ocular complications
keratitis dx
clin. findings, labs: NV: Gs, Cx, sens
viral: DFA, Cx, PCR
ophthalmology consult for HSV Ker. and VAV ker. to ID virus and det. epi or stromal forms (dendritic figures)
keratitis tx
non-viral agents: antimicr. tx to avoid perf, ulc, blindness: FQ eye drops (Ciloxan, Ocuflox)
HSV K: depends on K form
VZV keratitis: oral acyclovir (3 days)
retinitis
CMV retinitis HHV 5
retinitis most common viral sight/life threatening opp. inf. in
AIDS pts; poor px
retinitis path
recrudescence of latent CMV inv (waning CMI)
retinitis symps
unilateral–>bilat vision loss due to eye lesions–>visual field loss and dec. visual acuity
retinitis dx
red patches (hemorrhage) and white (necrosis, edema) over lg portions of retina vitreous clear and inflamm-free
retinitis tx
ganciclovier, foscarnet, cidofovir (IV, intravitreally, both)
this org. causes retinitis (not as common as viral CMV cause)
Tosoplasma gondii (protozoan, EUK) path: recrudescence of latent T. gondii inv (waning CMI)
other causes of retinitis
“salt and pepper lesions” of congenital rubella (German measles)
*HSV (prim and rec)
*VZV (prim and rec**)
*dis. in bot immcomp and CMI comp, poor ps despite high does IV acyclovir
Roth spots of infectious endocarditis
River blindness org
(Onchocerciasis)
parasitic worm: Onchocerca volvulus (helminth, tissue round worm, filarial nematode)
River blindness cycle
transmit. thru bites- blackflies (Simulium)
* *2nd leading cause of blindness ww! (after trachoma)
- microfilariae found in peripheral blood, urine, sputum, mostly skins and lymph. of CT (2y lifespan)
River blindness path
systemic, derm, ocular inf
symps caused by body’s resp to dead/dying larvae (rel. Wobachia bac)
-skin inflammation: itchy and damaging
-eye inflammation: rev. lesions on cornea–>if no tx, perm. clouding–>blindness
also optic nerve inflamm.–>vision loss (perish)–>blindness
River blindness s/s
itchy skin rashes: “leopard skin”, thinning: “cigarette-paper” “hanging groin”
nodules under skin
vision changes: loss of peri vision/blindness
occ. non painful swelling of lymph glands
River blindness tx
IVERMECTIN (ev. 6 mos as long as eye/skin inf)
**but make sure not Loa loa!!: sev. SEs (encephalopathy) to ivermectin*
