Signs and Symptoms of Conjunctivitis (Pink Eye)
Conjunctivitis presents with conjunctival injection (redness) plus additional inflammatory signs such as discharge, follicles, or papillary reactions, distinguishing it from simple conjunctival hyperemia. 1
Cardinal Signs and Symptoms
Primary Symptoms
- Eye discharge - character varies by etiology: purulent/mucopurulent (bacterial), watery (viral/allergic), or mucoid 2, 3
- Conjunctival injection (redness) - typically diffuse pattern in conjunctivitis 1
- Mattering and adherence of eyelids - particularly prominent in bacterial cases 2, 4
- Itching - strong indicator of allergic etiology 1, 3
- Tearing (epiphora) 2
- Irritation or foreign body sensation 2
- Photophobia - may indicate corneal involvement 2
- Blurred vision 2
Key Physical Examination Findings
Conjunctival Findings:
- Follicular reaction - small, dome-shaped elevations on tarsal conjunctiva, particularly inferior; suggests viral, chlamydial, or toxic etiology 2, 1
- Papillary reaction - velvety appearance of tarsal conjunctiva; suggests allergic or bacterial etiology 2, 1
- Chemosis - conjunctival edema 2, 1
- Subconjunctival hemorrhage - may occur with viral conjunctivitis 2
Eyelid and Adnexal Signs:
- Preauricular lymphadenopathy - particularly with viral conjunctivitis 2, 1
- Eyelid swelling and discoloration 2
- Vesicular rash or ulceration - suggests herpes simplex or varicella zoster virus 2
Corneal Involvement:
- Punctate epithelial keratitis - fine corneal staining 2
- Subepithelial infiltrates - particularly with epidemic keratoconjunctivitis 2
Etiology-Specific Presentations
Viral Conjunctivitis
- Abrupt onset, often unilateral initially becoming sequentially bilateral 2, 1
- Watery discharge 2, 3
- Follicular reaction of inferior tarsal conjunctiva 2
- Associated upper respiratory infection 2, 5
- Self-limited course, improving within 5-14 days 2, 1
Bacterial Conjunctivitis
- Mucopurulent discharge with eyelids matted shut 4, 3
- May remain unilateral 1
- More common in children 4, 3
Allergic Conjunctivitis
- Bilateral itching as predominant symptom 1, 3
- Watery discharge 3
- Papillary reaction, particularly giant papillae in severe cases 2
- Seasonal pattern often present 4
Critical Red Flags Requiring Ophthalmology Referral
Immediate referral indicated for: 2, 3
- Severe pain not relieved with topical anesthetics
- Decreased or blurred vision
- Corneal involvement or opacity
- Vesicular rash on eyelids or nose (herpes)
- Recent ocular surgery
- Neonatal conjunctivitis
- Immunocompromised state
- History of rheumatologic disease
- Distorted pupil
- Copious purulent discharge (gonococcal concern)
Common Diagnostic Pitfalls
Avoid overlooking serious conditions that may present with red eye: 1
- Acute angle-closure glaucoma - presents with severe pain, vomiting, and decreased vision 6
- Uveitis - perilimbal injection pattern, photophobia, decreased vision 1
- Scleritis - severe boring pain, sectoral deep redness 1
- Corneal ulcer - particularly in contact lens wearers 4, 3
Never prescribe topical corticosteroids or anesthetics in primary care without ophthalmology consultation - risk of worsening infectious keratitis and masking serious pathology 6
The pattern of redness matters: diffuse suggests conjunctivitis, sectoral suggests localized irritation, and perilimbal (circumcorneal) suggests more serious intraocular inflammation 1. The presence of discharge distinguishes true conjunctivitis from simple hyperemia 1.