anti allergics Flashcards
what does allergic eye disease take the form in
allergic eye disease affects between 15- 40% of the population and takes form of 2 main types , perennial allergic conjucitivits , and seasonal allergic conjuctivitis
as the name suggests perennial is not season dependent whereas seasonal is
what is perennial allergic conjuctivits
perennial =it is not seasonal
happens any time of year
what is sac also known as
seasonal allergic conjuctivitis would commonly be called hay fever and is due to an immunoglobulin e (lge) hypersensitivity reaction to pollen
most cases of allergic conjuctivittis are seasonal and present in spring or early summer
1st line in treatment - remove allergy
can be advised to wash eyes when they come back in to remove pollen or use artificial tear preparations
what is perinial allergic conjuctivits due to
due to lge hypersensitivity reaction to a range of allergens such as animal dander , mould spores or house dust mites
what type of drug is sodium clymograte
it is a mast cell stabiliser
describe the meahchnism of allergic conjuctivitis
allergic conjuctivitis is caused by an immunoglobulin (lge) response to an allergen
allergens bind to mast cells in the conjuctiva causing them to degranulate which initiates an inflammatory cascade
histamine and other inflammatory mediators are then released- release of histamine causes the itching , causes blood vessels to dilate causing conjuctivial hyperaemia - blood vessels leak , leak water causing oedema and thickens conjuctiva and you get discharge so the tears thicken
describe the mode of action of sodium crygolate
stabilises the mast cells and stops the degranulation and stops the inflammatory cascade of proteins which release histamine
SODIUM CRYGOLATE DOES NOT CAUSE DEGRANULATION THAT WOULD CAUSE AN ALLERGIC RESPONSE
what are the symptoms of allergic conjuctivitis
activiation of hist mine h1 receptors in the conjuctiva leads to ocular itching (the predominant feature of ocular allergy =)
other allergic symptoms (such as redness and swelling) (chemises) of the conjucitiva and eyelid swelling) have been attributed to stimulation of h1 and h2 receptors on blood vessels
allergic conjuctivits can be made worse If there are problems with the lids, lashes or tear film as this could allow more exposure to the allergens
how to differentiate between allergic conjucttivits and other types of conjuctivits
clinical presentation can be non specific but the hallmark symptom of allergic conuctivits is ocular itching (usually bilateral) if itching is no present an alternative should be considered
itching may also be described as burning or stinging
other features= water or mucoid discharge - sometimes referred to as ‘‘tearing’’ - discharge may be stringy or ropey due to the presence of a small amount of mucous
where does the discharge produced by allergic conjuctivits usually sit
the ropey stringer mucous usually sits in the tarsal conjuctivia
what are other presentations of allergic conjuctivits
conjucttival redness (hyperaemia) , injection
conjunctival swelling (chemossi) bulbar and tarsal conucitiva may budge over lid margin or limbus
conjunctival papillary reaction
eyelid oedema (swelling) periorbiarl oedema can occur in severe cases
what are the two key features that are really characteristic of allergic conjuctivits
itchy
swelling on the conjuctiva
what is the conjuctival papillary reaction
when looking under the lids there will be stringy mucoid discharge and also papillary response - typical appearance of tarsal conjuctiva should be smooth - if you see a papillary change i..e change to the papillae - suspect allergic conjucitivits
what is viral conjuctivitis associated with
- a follicular response on the tarsal conjuctiva most forms of bacterial conuctivits we dont see a response on the tarsal conjuctivitis
symptoms of allergic conjuctivits =
transient or subacute attacks of redness , watering , itching associated with sneezing and nasal discharge
conjunctival hyperaemia with relatively mild papillary reaction
how would you describe a picture of red eye
conjuctival injection = redness
if its all over described as generalised
if it looks red all over it is called a generalised conjuctival injection
what is the oedema of conjunctiva called
chemosis
what is hypoyon
when cells accumulate in the anterior chamber
in an exam what needs to be described to an examiner
- start with lids and lashes
then conjuctiva
then cornea
anterior chamber
iris
and crystalline lens
tear film
if they dont won’t you to avert lids - mention how you would normally avert the lids to see if there is a pupillary response or a follicular response
dont just talk about disease processes
what are the different parts of the conjuctiva
bulbar conuctiva
tarsal conjcucitva
if you see bumps on upper lid what is called
pupillae response of the tarsal conjuctiva
what is red appearance of the eye with spread out vessels described as
diffuse conjuctival injection
what are trantas dots a sign of
- sign of severe allergy- accumulation of cells -wbcs and other cells- not ulceractions
what might allergic conuctivits coexist with
rhinitis and rhinisunsuitis- nose and sinus
asthma
urticaria - general skin rashes
eczema
what might symptoms be exacerbated by
symptoms may be exacerbated of other eye conditions such as belepharitis or dry eye
if there is corneal involvement then consider kertacoconuuctivis which has the potential for serious complications and should receive a doctors opinion
what is sodium cromoglycate
a mast cell stabiliser - prevents them from degranulating and prevents the release of inflammatory mediators
how is sodium cromyglycate available if more than 10ml
pom medicine
how is sodium cromyglycate available if less than 10ml
p medicine
GSL if older than 6yrs and for not more than 14 days they have been classifies from p to gel for the relied and treatment of symptoms of hay fever , they are not to be used in children under 6 years for more than. 14 days
what is the action of sodium cromoglicate
mast cell stabiliser for the relief and treatment of seasonal and perennial allergic conjunctivas , available in a variety of trade names e.g. opticrom (sanofi) or cromulox (bausch and lomb) multi use preparations so contains benzalkonium chloride
is sodium cromoglicate available in the form of single use preperations
available in single use preparations
catacrom eeye drops - 2 percent sodium cromoglicate
opticrom
- allergy single does - eye drops - 2 percent sodium cromoglicate
what are the contraindications for sodium cromglycate use
contrainidacted in pts with hypersensitivity to sodium cromolgycate or any component of the preparation - should only be used in pregnancy when there is a clear clinical need - contact lense weares should remove lenses during treatment - - no reported interactions with other meds but if other drops are being used should be spaced by 5-10 mins
what is the dose of sodium crymoglycate
the dose is 1 or 2 drops to both eyes 4 times a day
store below 30 degrees and protect from direct sunlight
what anti histamines can be used
antalonline sulfate is a antihistamine
available ion the uk as otrivine anntisin antonazone sulfate
0.05% xylometazoline hydrochloride
what are contraindications to anti histamine use
hypersensitivity to antazoline
xynlometazonline
or any component oof the preparation
should not be used in pts who have taken monomania oxidase inhibits (MAOIS) within the previous 14 days
what patients should the anti histamine not be given too
the only preparation available in the uk contains xylometazoline which is a symphatomimmentic and should be avoided in patients at risk of angle closure
use with caution in elderly patients with severe cardivacualr disease , hypertension , cardiac irregularities , hyperthyroidism , diabetes mellitus and pahemcohryomcyttomas and in patients with conditions causing urniary retention (such as prostatic hypertrophy) or patients who are currently receiving other sympathomimetic drugs
what cautions should you be aware of when giving anti histamines
contact lenses should not be worn during treatnent, preparation contains benzalkonium chloride as a preservative , which may accumulate in soft lenses and cause irritation , contact lenses should bee removed prior to application and the patient should wait at least 15 mins before reinsertion
if someone is pregnat should anatazoline be given
no
the safety in pregnancy has not been established , should be used with caution during pregnancy and only if the expected benefit to the patient is greater than any possible risk to the developing foetus , it is not known weather anttozoline is excreted in breast milk, its use during great feeding therefore requires that the benefits outweigh the potential risk to the infant
what are the drug interactions of anatazoline
should not be used in pts receiving monomaime oxidase inhibitors (MAOIS) within 14 days of stopping such treatment (there is a risk of hypertensive crisis)
should be used with caution in pts receiving other medications such as digitalis (heart drug) , beta adrenergic blockers, guanethisdine , reesperine , methyldopoa or antihypertensive agents
what can sedating antihistamines enhance the effects of
sedating antihistamines can enhance the sedating effects of CNS, depressants , including alcohol , hypnotics , opioid analgesics , anxiolytic sedatives and antipsychotics , they also have an additive antimuscarnic action when taken with other antimuscarinic drugs such as atropine and some antidepressants
in the case of concomitant use of another topical eye preparation allow 5-10 minutes between each application of each preparation.
what is rebound hyerpermia
check angle status with van heroic test as the sympathomimetic effects of xylomeettazoline can lead to drug induced angle closure
rebound hyperaemia may occur following prolonged or frequent use
ocular side effects are uncommon and typically transient
there have been recent case reports of severe follicular conjuctivitis
