What is the diagnosis and treatment for recurring seasonal right eye redness, watering, and stinging, accompanied by headaches and nasal congestion?

Seasonal Allergic Rhinoconjunctivitis

This is seasonal allergic rhinoconjunctivitis (also called allergic rhinitis with allergic conjunctivitis), and you should treat it with dual-action topical antihistamine/mast cell stabilizer eye drops (such as olopatadine or ketotifen) combined with intranasal corticosteroids, starting 1-2 weeks before the expected symptom season. 1, 2

Diagnosis

The clinical presentation strongly supports seasonal allergic rhinoconjunctivitis based on:

• Seasonal pattern: Symptoms recurring at the same time annually indicate exposure to seasonal aeroallergens (tree, grass, or weed pollens) rather than perennial allergens 1
• Conjunctival symptoms: Right eye redness, watering, and stinging without itchiness represent allergic conjunctivitis, which occurs in over 75% of patients with seasonal allergic rhinitis 1
• Nasal congestion: Concurrent nasal symptoms during eye episodes confirm the rhinoconjunctivitis complex 1
• Headache pattern: Retro-orbital headache (2/10 pain behind right eye) with periods of remission/recurrence is consistent with sinus involvement from allergic rhinitis 3
• Previous response: Relief with anti-inflammatory eye drops supports an inflammatory allergic process 1

Important caveat: The absence of itching is somewhat atypical, as itching is usually the pathognomonic sign of allergic conjunctivitis 1, 4. However, the seasonal pattern, watering, and nasal congestion make allergic rhinoconjunctivitis the most likely diagnosis. The unilateral predominance (right eye) is also slightly unusual but does not exclude the diagnosis 1.

Treatment Algorithm

First-Line Therapy (Start Immediately)

For ocular symptoms:

• Dual-action topical agents (antihistamine + mast cell stabilizer): Olopatadine, ketotifen, epinastine, or azelastine are the most effective first-line treatments because they provide both rapid symptom relief and ongoing protection 1, 2
• Store drops in refrigerator for additional cooling relief upon instillation 1, 2
• These agents work better than either antihistamines or mast cell stabilizers alone and have rapid onset of action 2

For nasal symptoms:

• Intranasal corticosteroids: These are equally effective as oral antihistamines for both nasal AND ocular symptoms 1
• Intranasal corticosteroids, oral antihistamines, and intranasal antihistamines have similar effectiveness in relieving eye symptoms associated with rhinitis 1

Adjunctive measures:

• Refrigerated preservative-free artificial tears to dilute allergens and inflammatory mediators 1, 2
• Cold compresses for symptomatic relief 1
• Wear sunglasses as a physical barrier against airborne allergens 1, 2
• Avoid eye rubbing, which can worsen symptoms 1, 2

Timing Strategy (Critical for Seasonal Allergies)

• Start treatment 1-2 weeks BEFORE the expected pollen season to prevent the priming phenomenon 1
• The priming effect causes increased nasal sensitivity as the pollen season progresses, making symptoms harder to control if treatment is delayed 1
• At the end of pollen season, symptoms may decline more slowly than pollen counts due to priming 1

Second-Line Therapy (If Inadequate Response After 1-2 Weeks)

Add a brief course of topical corticosteroids:

• Loteprednol etabonate 0.5% is the preferred topical corticosteroid due to its low side effect profile 1, 2, 5
• Use for only 1-2 weeks maximum 1, 2
• Loteprednol is a C-20 ester corticosteroid that is less likely to elevate intraocular pressure compared to traditional ketone corticosteroids 5, 6
• Monitor intraocular pressure at baseline and periodically if corticosteroids are used 2, 5

Alternative for itching (if it develops):

• Topical NSAID (ketorolac tromethamine) provides temporary relief of ocular itching in seasonal allergic conjunctivitis 1, 2, 7
• However, ketorolac offers little advantage over topical antihistamines for most patients 8

Third-Line Therapy (For Severe or Refractory Cases)

• Topical cyclosporine 0.05% or tacrolimus for cases unresponsive to above treatments 1, 2
• Allergen immunotherapy should be considered for patients intolerant or refractory to medications 8, 9

Critical Pitfalls to Avoid

• Do NOT use oral antihistamines as primary treatment: They may worsen dry eye syndrome and impair the tear film's protective barrier, potentially worsening allergic conjunctivitis 1, 2
• Avoid prolonged vasoconstrictor use: Over-the-counter antihistamine/vasoconstrictor combinations can cause rebound hyperemia (conjunctivitis medicamentosa) with chronic use beyond 10 days 1, 2
• Do NOT use topical antibiotics: They are not indicated for allergic conjunctivitis and can induce toxicity 1
• Avoid punctal plugs: They prevent flushing of allergens and inflammatory mediators from the ocular surface 2
• Do NOT use topical corticosteroids indiscriminately: They can prolong viral infections if misdiagnosed and require IOP monitoring 1, 2

Environmental Modifications

• Hypoallergenic bedding to reduce allergen exposure 1
• Eyelid cleansers to remove allergens from lashes and lid margins 1
• Frequent clothes washing after outdoor exposure 1
• Shower/bathe before bedtime to remove allergens from hair and skin 1
• Keep windows closed during high pollen count days 1

When to Refer

• Vision changes develop (rule out vision-threatening conditions like vernal or atopic keratoconjunctivitis) 1
• Symptoms persist despite appropriate therapy for 2-4 weeks 1
• Need for prolonged topical corticosteroid use (requires ophthalmology monitoring) 1, 2
• Consider allergy testing to identify specific allergens for targeted avoidance and potential immunotherapy 1