Allergic Conjunctivitis Flashcards
Different types of hypersensitivity response
- type 1 - IgE mediated
- type 2 - cytotoxic
- type 3 - immune complex
- type 4 - delayed hypersensitivity
Signs/symptoms of allergic reaction
- itching
- redness
- swelling
- discharge
Subtypes of ocular allergy
- acute ocular allergy
- seasonal and perennial
- vernal
- atopic
- CLAPC
Appearance of papillae
- central vascular nodule
- flat topped
- larger
Appearance of follicles
- lack a prominent central vessel
- dome shaped
- always small
Differential diagnosis of allergic eye disease
- infective conjunctivitis
- dry eye
- foreign bodies
- episcleritis
Types of anti allergy drugs
- mast cell stabilisers
- antihistamines
What are mast cell stabilisers
- prevents mast cell degranulation
- stops release of inflammatory mediators
- no effect on histamine already released
- delay up to 2 weeks
- useful for long term allergies
- prophylactic
Examples of mast cell stabilisers
- sodium cromoglicate
- lodoxamide
Sodium cromoglicate medicinal forms and restrictions
Medicinal forms
- topical
- sodium cromoglicate 2% (opticrom)- GSL
- sodium cromoglicate 2% (optrex allergy)- P
- sodium cromoglicate 2% (generic) - PoM
SODIUM CROMOGLICATE dose, cautions, interactions and contraindications
Dose
- qds
Cautions
- none
Interactions
- none
Contraindications
- hypersensitivity to ingredients
Lodoxamide medicinal forms and dose
Form
- lodoxamide 0.1% (Alomide) PoM
Dose
- qds
- not for use under 4 yrs
Undesirable effects of lodoxamide
Common
- dry eye
- discomfort
Uncommon
- corneal deposits
- dizziness
- eye inflammation
- headache
Rare
- rash
- altered taste
Systemic Antihistamine drug examples
Chlorphenamine
Loratadine
Oloptadine
Ceterizine
Chlorphenamine mechanism, dose and contraindications
- H1 blocking drug
- sedating effects
- oral table or syrup
Dose
- 4mg up to qds
- from 1 yrs old
Contraindications
- hypersensitivity to active ingredient
- px being treated with monoamine oxidase inhibitors
Loratadine mechanism, forms and dose
Mechanism
- second generation H1 blocking drug
Forms
- Loratadine 10mg (generic) PoM
- Loratadine 10mg (clarityn allergy) GSL
Dose
- 10mg daily in adults
Oloptadine mechanism, forms and dose
Mechanism
- selective H1 blocker
Forms
- Oloptadine 1mg/ml PoM
Dose
- bds for up to 4 months
Oloptadine indications and side effects
Indications
- seasonal allergic conjunctivitis
Effects
- dry eye
- irritation
- headaches
- eye pain
- headache
- nasal dryness
Mechanism and indication for topical ocular decongestants
- adrenergic alpha agonists
- mimic action of sympathetic branch of autonomic nervous system
- constriction of blood vessels
- vasocontrictive action
- reduces hyperaemia
Indications
- temporary relief from eye pain
- 2-3 times per day
Cautions and sideffects of ocular decongestants
- not for use under 12
- 7 day max tx time
- excessive use may produce rebound
Systemic effects
- cardiovascular disorders
- arrhythmia
- high blood pressure
- diabetes
Mechanism of Type 1 reaction
- IgE mediated
- produced after 1st exposure
- bind to mast cells
- smooth muscle contraction, vasodilation increased permeability
Mechanism of type 4 reaction
- T cells
- 48-72 hrs after exposure
- release of cytokines which attract lymphocytes macrophages and basophils
Sodium cromoglicate licensing
GSL
- seasonal conjunctivitis qds
- not for under 6
PoM
- acute allergic conjunctivitis
- chronic allergic conjunctivitis
- vernal keratoconjunctivitis
Lodoxamide indications
- allergic conjunctivitis
