A 28-year-old woman presents with acute onset bilateral conjunctival injection, watery discharge, and mild foreign body sensation for 2 days. She reports recent upper respiratory tract infection. Examination reveals follicular reaction on tarsal conjunctiva and preauricular lymphadenopathy. All of the following are characteristic features of viral conjunctivitis EXCEPT:

Explanation

## Distinguishing Viral from Bacterial Conjunctivitis ### Clinical Presentation of Viral Conjunctivitis **Key Point:** Viral conjunctivitis typically presents with watery or mucoid discharge, NOT purulent discharge. Purulent discharge with matting of eyelids is a hallmark of bacterial conjunctivitis, not viral. ### Characteristic Features of Viral Conjunctivitis | Feature | Viral | Bacterial | |---------|-------|----------| | Discharge | Watery, mucoid | Purulent, mucopurulent | | Eyelid matting | Absent or mild | Present, marked | | Follicular reaction | Common (tarsal) | Absent or minimal | | Preauricular lymph nodes | Present (hallmark) | Absent | | Pseudomembrane | May occur (severe cases) | Rare | | Conjunctival injection | Diffuse | Localized or diffuse | **High-Yield:** The presence of **preauricular lymphadenopathy** is a cardinal sign of viral conjunctivitis and helps differentiate it from bacterial causes. **Clinical Pearl:** Follicular reaction (small lymphoid aggregates on tarsal conjunctiva) is a hallmark of viral conjunctivitis and indicates lymphocytic infiltration. ### Why Purulent Discharge is Bacterial, Not Viral 1. Purulent discharge indicates neutrophilic inflammation — characteristic of bacterial infection 2. Eyelid matting (crusting that seals eyelids shut, especially on waking) occurs with bacterial conjunctivitis 3. Viral conjunctivitis produces watery or thin mucoid discharge that does not cause matting **Mnemonic:** **VIRAL** = **V**atery discharge, **I**nfection (preauricular nodes), **R**eaction (follicular), **A**cute onset, **L**ymphoid aggregates [cite:Park 26e Ch 10]