🎧Deep Dive: AllergicConjunctivitis – MSRA Ophthalmology Essentials

You know that itchy,watery, red-eye feeling—especially during spring or when your pet curls up nextto you? That’s where today’s deep dive begins. We're unpacking allergic conjunctivitis — what it is, whatcauses it, and how to manage it effectively, especially for your MSRA prep.

👁️What Is It?

An inflammation of the conjunctiva triggered byallergens like pollen, pet dander, or dust mites. It's your immune systemoverreacting to harmless substances.

🧬Pathophysiology

Exposure toallergens → IgE binds to mast cells →release of histamine and inflammatory mediators→ itching, redness, watering, and swelling.

📌Key Risk Factors

• Personal or familyhistory of atopy (eczema, asthma,allergic rhinitis)

• Seasonal pollenexposure (hay fever overlap)

• Indoor allergens(dust mites, pets)

• Contact lens use(risk of Giant Papillary Conjunctivitis)

🧠Symptoms & Signs

• Intense itching – the hallmark symptom

• Bilateral red, watery eyes

• Puffy eyelids,chemosis (conjunctival swelling), papillae under lids

• History ofseasonal allergy or atopic conditions

❗DifferentialDiagnosis

Don’t confuse itwith:

• Infective conjunctivitis (viral/bacterial –sticky discharge)

• Uveitis, keratitis (pain, photophobia, visionloss)

• Blepharitis, scleritis, glaucoma – especiallyif pain, photophobia, or unilateral

🔍 Always ask: Is it itchy or painful? Pain = red flag 🚨

📊Epidemiology

• Affects up to 40% of the population

• Common in childrenand young adults

• Oftenunderdiagnosed

• Peaks in spring/summer (pollen), but can be perennial (dust/pets)

🩺Diagnosis

✅ Primarily clinical

✅ Based on history + bilateral itch/redness

🔬 Investigations (if needed):

• Conjunctival swab(to exclude infection)

• Allergy testing(if severe/recurrent)

• Slit lamp exam(for papillae, corneal involvement)

• Fluoresceinstaining (if keratitis suspected)

💊Management (UKNICE-Based)

1️⃣Avoidance – limit allergen exposure

2️⃣Cool compresses +artificial tears

3️⃣Topicalantihistamines – fast symptom relief

4️⃣Mast cell stabilisers – prevent recurrence

5️⃣Oral antihistamines – useful if hay fever present

6️⃣Steroid eye drops – only under ophthalmology care

🚫 Avoid rubbing eyes – it worsens inflammation!

📈When to Refer

🔺 Severe or persistent symptoms

🔺 Need for topical steroids

🔺 Unclear diagnosis

🔺 Suspected sight-threatening causes (uveitis,keratitis, etc.)

📅Prognosis

✅ Excellent in most common forms(seasonal/perennial)

⚠️Vernal and atopickeratoconjunctivitis carry risk ofcorneal damage – need specialist input

✅ Vision usually well preserved with proper care

🧠MSRA Key Takeaways

• Itch = Allergy

• Bilateral, red,watery eyes = classic

• Atopy is a strongclue

• Rule out painful, unilateral, or vision-threateningcauses

• Topicalantihistamines + stabilisers = 1st-line

• Refer if red flagsor steroid needed

🎓 Mnemonic: ITCH = Intense Tearing, Chemosis, Hyperaemia

🧰 Management: Avoid, Antihistamines, Artificial tears, Atropine(stabiliser)

📤 Referral if Pain, Photophobia, Poor vision

📚Revision Links

📝 Notes: https://www.passthemsra.com/topic/allergic-conjunctivitis-revision-notes/

🧠 Flashcards: https://www.passthemsra.com/topic/allergic-conjunctivitis-flashcards/

❓ Accordion Q&A: https://www.passthemsra.com/topic/allergic-conjunctivitis-accordion-qa-notes/

🔥 Rapid Quiz: https://www.passthemsra.com/topic/allergic-conjunctivitis-rapid-quiz/

🧪 Quiz Bank: https://www.passthemsra.com/quizzes/allergic-conjunctivitis/

🎓 For more structured MSRA revision, visit:

🌐https://passthemsra.com

🌐https://freemsra.com