Conjunctivitis:

Patient presenting to the Emergency Department complaining of "Pink Eye" is very common but how can you be sure that they do not have a bacterial conjunctivitis and absolutely need antibiotics or are they just suffering from a viral or allergic conjunctivitis.

• Bacterial conjunctivitis will typically have  a mucopurulent discharge and the patients will complain that their lids are matted shut in the morning. Though this can occur in allergic or viral conjunctivitis, those with bacterial conjunctivitis typically have a wet, sticky mucopurulent material matted to their lids where viral/allergic conjunctivitis typically have crusting on their lids and lashes due to dried tears and serous secretions.  Bacterial conjunctiviits is also an uncommon condition due to the defense systems of the eye. So most patients can be treated with support care (ie: Warm Compresses).
• Allergic conjunctivitis should affect both eyes.  It would be odd for only one eye to be allergic, so if only one eye is infected that diagnosis is most likely viral or bacterial conjunctivitis.
• When treating allergic conjunctivitis go with the drops.  Several studies have now shown that topical therapy is better than systemic (ie: benadryl, zyrtec, allegra, or claritin) in the resolution of symptoms.