Causes of Red Eye and Nasal Congestion
Red eye with nasal congestion most commonly results from allergic rhinoconjunctivitis, where airborne allergens trigger both ocular and nasal inflammation simultaneously. 1
Primary Etiologies
Allergic Rhinoconjunctivitis
This represents the most likely diagnosis when red eye and nasal congestion occur together. The American Academy of Otolaryngology-Head and Neck Surgery identifies this condition by the constellation of nasal congestion, clear rhinorrhea, red and watery eyes, and pale discoloration of nasal mucosa. 1 Key distinguishing features include:
- Bilateral presentation with itching as the most consistent symptom 2
- Watery (not purulent) discharge from eyes 2
- Seasonal or perennial pattern depending on allergen exposure 2
- Concurrent symptoms: sneezing, runny nose, nasal pruritus 1
- Absence of preauricular lymphadenopathy or matted eyelids 2
Viral Upper Respiratory Infection with Conjunctivitis
Viral conjunctivitis frequently accompanies upper respiratory infections, presenting with: 2
- Abrupt onset, often starting unilateral but becoming sequentially bilateral 2
- Watery discharge with follicular reaction on inferior tarsal conjunctiva 2
- Preauricular lymphadenopathy (especially with adenovirus) 2
- Self-limited course resolving within 5-14 days 2
Infectious Rhinosinusitis with Secondary Ocular Involvement
The American Academy of Allergy, Asthma & Immunology notes that distinguishing noninfectious rhinitis from acute sinusitis can be difficult because symptoms overlap, including mucosal erythema, nasal congestion, and associated eye redness. 1
Critical Differentiating Features
To distinguish between these causes, focus on:
- Discharge character: Clear/watery suggests allergic or viral; purulent indicates bacterial infection 2, 3
- Itching intensity: Prominent itching strongly favors allergic etiology 2
- Nasal mucosa appearance: Pale and boggy suggests allergy; erythematous suggests infection 1
- Bilateral vs unilateral: Allergic is always bilateral; viral often starts unilateral 2
- Seasonal pattern: Recurrent seasonal symptoms indicate allergic cause 1
Associated Conditions Requiring Assessment
The American Academy of Otolaryngology-Head and Neck Surgery recommends documenting presence of: 1
- Asthma (frequently coexists with allergic rhinoconjunctivitis) 1
- Atopic dermatitis 1
- Sleep-disordered breathing 1
- Chronic rhinosinusitis 1
Red Flags Requiring Immediate Ophthalmology Referral
Refer urgently if any of the following are present: 2
- Visual loss or decreased vision 2
- Moderate to severe eye pain 2
- Corneal involvement 2
- Severe purulent discharge 2
- History of herpes simplex virus eye disease 2
- Immunocompromised status 2
Common Pitfalls to Avoid
Do not use topical corticosteroids indiscriminately, as they can prolong adenoviral infections, worsen herpes simplex infections, and cause increased intraocular pressure. 1, 2 The American Academy of Ophthalmology specifically warns against indiscriminate antibiotic use for viral conjunctivitis, which provides no benefit and may cause toxicity. 2
Avoid prolonged use of ocular decongestants beyond 10 days, as this leads to rebound hyperemia ("conjunctivitis medicamentosa"). 1