wk6: AED - Allergy 2 [DG] Flashcards
List the symptoms of VKC (8)
intense itching/burning
watery
photophobia
FB sensation
puffy lids
mucoid discharge
blurred vision
eye rubbing
List the signs of VKC (7)
symptoms may worsen in spring + early summer
type 1 hypersensitivity
uncommon, bilateral, males>females
most common age @5-25yrs
most sufferers atopic (people with other allergies) or have family hx of atopy
usually affects superior tarsal conjunctiva but may affect limbal area (or could affect both)
List the clinical features of VKC (8)
bilateral
conjunctival hyperaemia + chemosis
large palpebral papillae (up to 5mm)
stringy mucus dicharge (may sit b/w papillae)
ptosis
Corneal changes: SPK, shield ulcers, subepithelial scarring, eosinophil plaques
Limbus: limbitis with limbal papillae + Horner-Trantas’ dots, and pseudogerontoxon
How does VKC present in the cornea? (4)
SPK, shield ulcers, subepithelial scarring, eosinophil plaques
How does VKC present at the limbus? (3)
limbitis with limbal papillae + Horner-Trantas’ dots, and pseudogerontoxon in area of previously inflamed limbus
What DDx exist for VKC? (2)
atopic keratoconjunctivitis
giant papillary conjunctivitis
How do you assess VKC? (4)
hx, slit lamp, fluoroscein, lid eversion
Describe the pathophysiology of VKC, in relation to Th2 lymphocytes and what they mediate (2)
Th2 lymphocytes mediate:
- reduced IgE via IL-4
- differentiation + activation of mast cells & eosinophils via IL-3 and IL-5 respectively
What might explain improvement in VKC with onset of puberty?
over expression of oestrogen and progesterone receptors in the conjunctiva of VKC patients
What might VKC patients have a hypersensitivity to? (3)
wind, dust, sun
is their a genetic component behind VKC?
Possibly, research has found reduced level of tear film histamine
List tx options for VKC (6)
allergen avoidance (if identifiable, role for allergist)
topical MC inhibitors
corticosteroids
topical NSAIDs
topical cyclosporin
referral for superficial keratectomy to improve resolution of shield ulcer
Name 2 topical MC inhibitors that can tx VKC
Olapatidine (patanol iBD), Ketoifen (zatiden iBD)
Name a corticosteroid that can tx VKC, when would you schedule follow up after using it?
Fluorometholone (FML/Flarex iBD - iQID) - follow up one week after starting therapy
Name 2 topical NSAIDs that can tx VKC
Ketorolac (acular iQID), Diclofenac (voltaren iTDS-iQ3h)
How often should you follow up a VKC px if they have a shield ulcer?
every 1-3 days
How often should you follow up a VKC px during exacerbations?
every few weeks
How often should you follow up a VKC px between exacerbations? (i.e when exacerbations not happening)
less frequently (less frequently than every few weeks)
What type of IOP measurement would be best for VKC patients? Why?
Non-contact tonometry, b/c thin cornea
When do shield ulcers form?
when superficial punctate keratitis (SPK) associated VKC leads to a break in the corneal epithelium
Name the mechanisms that have been proposed to explain the pathogenesis of VKC-associated shield ulcers? (2)
Mechanical and toxin hypotheses
Explain the mechanical hypothesis for VKC associated shield ulcer pathogenesis
Mechanical: suggests giant papillae on upper tarsal conjunctiva are responsible for corneal abrasion
Explain the toxin hypothesis for VKC associated shield ulcer pathogenesis
Toxin: suggests that eosinophil granule major basic protein found in the inflammatory debris covering VKC shield ulcers is cytotoxic and inhibits wound healing of the corneal epithelium
Which hypothesis of VKC associated shield ulcer pathogenesis might explain ulcer re-epithelialization after the inflammatory debris is removed?
Toxin hypothesis
Which hypothesis explains the more common shield ulcers?
Mechanical hypothesis
Are VKC and AKC often misdiagnosed as each other? Does it matter?
yes, often. DDx usually doesn’t matter at the start
Compare the incidence of VKC with AKC in terms of ages (2)
VKC: 5-25yrs
AKC: early adulthood, post-puberty
How do the symptoms of atopic keratoconjunctivitis (AKC) compare with VKC?
Basically the same
In regards to AKC:
- What type of hypersensitivity is AKC?
- how common, unilateral or bilateral, which sex affect more?
type 1
uncommon, bilateral, affects males>females
How many AKC px are atopic with associated skin disease?
Most
What organisms/conditions are AKC patients prone to? (3)
Staph. blepharitis and HSV disease
How does AKC affect incidence of keratoconus and retinal detachment?
Increases
How common can AKC patients experience anterior subcapsular cataract?
rare (is usually due to these patients using strong steroids)
What signs of AKC can present in the skin? (1)
atopic dermatitis (e.g. in wrists, neck, eyelids)
What signs of AKC can present in the lids? (3)
eyelids thickened, crusty, ptosis
What signs of AKC can present in the conjunctiva? (3)
mainly inferior involvement
papillary hypertrophy, fibrosis, scarring
limbal cystic lesions or papillae
What signs of AKC can present in the cornea? (3)
SPK
shield ulcers
horner-trantas’ dot
What DDx exists for AKC? (2)
VKC, GPC
How can we assess AKC? (10)
hx
slit lamp
fluoroscein
lid eversion
lid margins
lens
corneal topography
DFE
skin
referral to allergist
List the tx options for AKC (6)
allergen avoidance, flushing of conj, hypoallergenic bed
topical AH, MCS, NSAIDs as per VKC
corticosteroids [aggressive]
topical cyclosporin
avoid eye rubbing
follow up regularly and as tx mode dictates (see VKC)
What corticosteroid can be used to tx AKC?
Flarex/Maxidex iTDS to Q2h with aggressive taper
Why should you not undertreat with steroids?
because if you do undertreat, you’ll get long term accumulation of steroid exposure, which can lead to cataract, etc.
Compare VKC with AKC for the following:
A: age onset
B: sex
C: seasonal variation
D; discharge
E: conj scarring
F; horner trantas dots
G; corneal neovascularisation
H: presence of eosinophils in conj scraping
VKC AKC
A: younger 2nd-3rd decade
B: males no sex favorite
C: spring perennial
D: thick mucoid watery/clear
E: moderate higher incidence
F: common rare
G: no yes, generally
H: more less
List the symptoms of GPC (5)
redness
burning
itch
FB sensation
increased lens awareness in CL wearers
What type of allergies is GPC associated with? (5)
allergies to:
CLs
CL deposits
solution preservatives
ocular prosthesis
protruding sutures
What advancement in tech has made GPC perhaps less common?
perhaps less common since advent of disposable CLs and kinder preservatives in solutions
Describe the features of:
- grade 1 GPC (3)
- grade 2 GPC (3)
- grade 3 GPC (3)
- grade 4 GPC (3)
Grade 1: slight conjunctival redness with fine papillae and no symptoms
Grade 2: mild injection, 0.3mm-0.5mm papillae, mild symptoms
Grade 3: moderate injection, 0.5mm+ papillae with increasing CL awareness
Grade 4: severe injection, 0.75mm+ papillae with lens intolerance
How can we assess GPC? (5)
hx
slit lamp
fluoroscein
lid eversion
inspection of CLs/prosthesis
List tx options for GPC (5)
MCS for several months (if less severe)
Topical steroid shorter term (more severe)
Advise px re CL care + overwear, non preserved sol.s
New contact lenses (refit) - daily lenses?
Removal of sutures
Name 2 conditions that fall under the category of autoimmune conjunctivitis. How common are they?
Cicatricial pemphigold
Steven-Johnson syndrome
These are rare
Continue later
Oh man oh man
