Opthalmology 2 Flashcards
What is the most commonly used allergy test?
Skin prick test
It is easy to perform and inexpensive.
What is the purpose of the Radioallergosorbent test (RAST)?
Determines the amount of IgE that reacts specifically with suspected or known allergens
Results are given in grades from 0 (negative) to 6 (strongly positive).
When are blood tests used in allergy testing?
When skin prick tests are not suitable
Examples include extensive eczema or when the patient is taking antihistamines.
What does skin patch testing help diagnose?
Contact dermatitis
Around 30-40 allergens are placed on the back.
What triggers Oral Allergy Syndrome (OAS)?
Cross-reaction with a non-food allergen, usually birch pollen
OAS presents with mild tingling or pruritus of the lips, tongue, and mouth.
How does OAS differ from food allergies?
OAS is caused by cross-sensitisation to a structurally similar allergen in pollen
Food allergies are caused by direct sensitivity to a protein present in food.
What is the most common pollen allergy associated with OAS?
Birch pollen allergy
What symptoms indicate OAS?
Itching and tingling of the lips, tongue, and mouth
Symptoms typically resolve within one hour of contact.
What is the recommended management for OAS?
Avoidance of culprit foods
Oral antihistamines can be taken if symptoms develop.
What characterizes systemic allergic reactions to venom?
Cutaneous reactions distant from the exposure site, such as widespread redness, itching, urticaria, and/or angioedema
What is the emergency management for anaphylaxis?
Intramuscular adrenaline, intravenous steroids, and intravenous antihistamines
Oxygen and nebulised bronchodilators may also be required.
What is Venom Immunotherapy (VIT) used for?
Effective immunotherapy for patients with a history of systemic reactions to venom
It is recommended for patients with raised levels of venom-specific immunoglobulin E.
What is the most important modifiable risk factor for thyroid eye disease?
Smoking
What are common features of thyroid eye disease?
Exophthalmos, conjunctival oedema, optic disc swelling, ophthalmoplegia
Inability to close eyelids may lead to sore, dry eyes.
What is the most common complication of thyroid eye disease?
Exposure keratopathy
Caused by eyelid retraction and proptosis.
What is a serious complication of thyroid eye disease?
Optic neuropathy
It occurs due to compression of the optic nerve by enlarged extraocular muscles.
What is acute angle-closure glaucoma (AACG)?
A rise in intraocular pressure secondary to impaired aqueous outflow
What are the features of AACG?
Severe pain, decreased visual acuity, hard red-eye, haloes around lights, semi-dilated non-reacting pupil
Symptoms may include systemic upset like nausea and vomiting.
What is the emergency treatment for AACG?
Combination of eye drops and intravenous acetazolamide
Definitive management includes laser peripheral iridotomy.
What does anterior uveitis refer to?
Inflammation of the anterior portion of the uvea, including the iris and ciliary body
What are common features of anterior uveitis?
Acute onset, ocular discomfort, photophobia, blurred vision, red eye
May also present with hypopyon.
What is scleritis?
Full-thickness inflammation of the sclera
It typically has a non-infective cause.
What are the risk factors for scleritis?
Rheumatoid arthritis, systemic lupus erythematosus, sarcoidosis, granulomatosis with polyangiitis
What is the typical management for corneal abrasions?
Topical antibiotic to prevent secondary bacterial infection