wk6: AED - Allergy 2 [DG]

Question 1

List the symptoms of VKC (8)

Answer 1

intense itching/burning
watery
photophobia
FB sensation
puffy lids
mucoid discharge
blurred vision
eye rubbing

Question 2

List the signs of VKC (7)

Answer 2

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)

Question 3

List the clinical features of VKC (8)

Answer 3

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

Question 4

How does VKC present in the cornea? (4)

Answer 4

SPK, shield ulcers, subepithelial scarring, eosinophil plaques

Question 5

How does VKC present at the limbus? (3)

Answer 5

limbitis with limbal papillae + Horner-Trantas’ dots, and pseudogerontoxon in area of previously inflamed limbus

Question 6

What DDx exist for VKC? (2)

Answer 6

atopic keratoconjunctivitis

giant papillary conjunctivitis

Question 7

How do you assess VKC? (4)

Answer 7

hx, slit lamp, fluoroscein, lid eversion

Question 8

Describe the pathophysiology of VKC, in relation to Th2 lymphocytes and what they mediate (2)

Answer 8

Th2 lymphocytes mediate:

• reduced IgE via IL-4
• differentiation + activation of mast cells & eosinophils via IL-3 and IL-5 respectively

Question 9

What might explain improvement in VKC with onset of puberty?

Answer 9

over expression of oestrogen and progesterone receptors in the conjunctiva of VKC patients

Question 10

What might VKC patients have a hypersensitivity to? (3)

Answer 10

wind, dust, sun

Question 11

is their a genetic component behind VKC?

Answer 11

Possibly, research has found reduced level of tear film histamine

Question 12

List tx options for VKC (6)

Answer 12

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

Question 13

Name 2 topical MC inhibitors that can tx VKC

Answer 13

Olapatidine (patanol iBD), Ketoifen (zatiden iBD)

Question 14

Name a corticosteroid that can tx VKC, when would you schedule follow up after using it?

Answer 14

Fluorometholone (FML/Flarex iBD - iQID) - follow up one week after starting therapy

Question 15

Name 2 topical NSAIDs that can tx VKC

Answer 15

Ketorolac (acular iQID), Diclofenac (voltaren iTDS-iQ3h)

Question 16

How often should you follow up a VKC px if they have a shield ulcer?

Answer 16

every 1-3 days

Question 17

How often should you follow up a VKC px during exacerbations?

Answer 17

every few weeks

Question 18

How often should you follow up a VKC px between exacerbations? (i.e when exacerbations not happening)

Answer 18

less frequently (less frequently than every few weeks)

Question 19

What type of IOP measurement would be best for VKC patients? Why?

Answer 19

Non-contact tonometry, b/c thin cornea

Question 20

When do shield ulcers form?

Answer 20

when superficial punctate keratitis (SPK) associated VKC leads to a break in the corneal epithelium

Question 21

Name the mechanisms that have been proposed to explain the pathogenesis of VKC-associated shield ulcers? (2)

Answer 21

Mechanical and toxin hypotheses

Question 22

Explain the mechanical hypothesis for VKC associated shield ulcer pathogenesis

Answer 22

Mechanical: suggests giant papillae on upper tarsal conjunctiva are responsible for corneal abrasion

Question 23

Explain the toxin hypothesis for VKC associated shield ulcer pathogenesis

Answer 23

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

Question 24

Which hypothesis of VKC associated shield ulcer pathogenesis might explain ulcer re-epithelialization after the inflammatory debris is removed?

Answer 24

Toxin hypothesis

Question 25

Which hypothesis explains the more common shield ulcers?

Answer 25

Mechanical hypothesis

Question 26

Are VKC and AKC often misdiagnosed as each other? Does it matter?

Answer 26

yes, often. DDx usually doesn't matter at the start

Question 27

Compare the incidence of VKC with AKC in terms of ages (2)

Answer 27

VKC: 5-25yrs AKC: early adulthood, post-puberty

Question 28

How do the symptoms of atopic keratoconjunctivitis (AKC) compare with VKC?

Answer 28

Basically the same

Question 29

In regards to AKC: - What type of hypersensitivity is AKC? - how common, unilateral or bilateral, which sex affect more?

Answer 29

type 1 | uncommon, bilateral, affects males>females

Question 30

How many AKC px are atopic with associated skin disease?

Answer 30

Most

Question 31

What organisms/conditions are AKC patients prone to? (3)

Answer 31

Staph. blepharitis and HSV disease

Question 32

How does AKC affect incidence of keratoconus and retinal detachment?

Answer 32

Increases

Question 33

How common can AKC patients experience anterior subcapsular cataract?

Answer 33

rare (is usually due to these patients using strong steroids)

Question 34

What signs of AKC can present in the skin? (1)

Answer 34

atopic dermatitis (e.g. in wrists, neck, eyelids)

Question 35

What signs of AKC can present in the lids? (3)

Answer 35

eyelids thickened, crusty, ptosis

Question 36

What signs of AKC can present in the conjunctiva? (3)

Answer 36

mainly inferior involvement papillary hypertrophy, fibrosis, scarring limbal cystic lesions or papillae

Question 37

What signs of AKC can present in the cornea? (3)

Answer 37

SPK shield ulcers horner-trantas' dot

Question 38

What DDx exists for AKC? (2)

Answer 38

VKC, GPC

Question 39

How can we assess AKC? (10)

Answer 39

``` hx slit lamp fluoroscein lid eversion lid margins lens corneal topography DFE skin referral to allergist ```

Question 40

List the tx options for AKC (6)

Answer 40

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)

Question 41

What corticosteroid can be used to tx AKC?

Answer 41

Flarex/Maxidex iTDS to Q2h with aggressive taper

Question 42

Why should you not undertreat with steroids?

Answer 42

because if you do undertreat, you'll get long term accumulation of steroid exposure, which can lead to cataract, etc.

Question 43

``` 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 ```

Answer 43

``` 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 ```

Question 44

List the symptoms of GPC (5)

Answer 44

``` redness burning itch FB sensation increased lens awareness in CL wearers ```

Question 45

What type of allergies is GPC associated with? (5)

Answer 45

``` allergies to: CLs CL deposits solution preservatives ocular prosthesis protruding sutures ```

Question 46

What advancement in tech has made GPC perhaps less common?

Answer 46

perhaps less common since advent of disposable CLs and kinder preservatives in solutions

Question 47

Describe the features of: - grade 1 GPC (3) - grade 2 GPC (3) - grade 3 GPC (3) - grade 4 GPC (3)

Answer 47

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

Question 48

How can we assess GPC? (5)

Answer 48

``` hx slit lamp fluoroscein lid eversion inspection of CLs/prosthesis ```

Question 49

List tx options for GPC (5)

Answer 49

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

Question 50

Name 2 conditions that fall under the category of autoimmune conjunctivitis. How common are they?

Answer 50

Cicatricial pemphigold Steven-Johnson syndrome These are rare

Question 51

Continue later

Answer 51

Oh man oh man