Five Things You Didn't Know About Pink Eye

1. You probably don't have a bacterial infection. If you've been diagnosed with pink eye (acute conjunctivitis) the far and away most likely cause of your infection is a virus.  Research suggests that as much as 80% of acute conjunctivitis episodes are viral.  Bacterial conjunctivitis is significantly less likely, which is why the use of antibiotics when diagnosed with pink eye is very controversial (using antibiotics when you don't have bacterial infections increases the risk of resistant bacterial strains).

2. Yes, you should see an EYE doctor. Your eye doctor can tell the difference between viral, bacterial, and other types of conjunctivitis, but getting the proper diagnosis elsewhere will be a challenge.  A 2008 review study reported that in primary care facilities conjunctivitis is correctly diagnosed less than 50% of the time. In order to determine the nature of your eye infection, a doctor needs specialized equipment that just won't be found at your primary care or urgent care facility.  The good news: your eye doctor can tell which type of infection you have by using the slit lamp microscope and sodium fluorescein dye staining to assess the conjunctiva and cornea.  They may even have a test for viral ocular infections called AdenoPlus that confirms adenovirus strains found in many viral infections with a quick n-office sample. Head to this post to learn more about the difference between the appearance of viral and bacterial conjunctivitis.

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Viral infections classically have follicular reactions in the palpebral conjunctiva.  With a slit lamp microscope your eye doctor can tell the difference between follicles (a lymphatic reaction) seen here above, versus papillae (an allergic or bacterial sensitivity reaction) seen below that is more classic for allergies or bacterial conjunctivitis.  Can you see the difference?

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3. If you are feeling miserable, puffy, and swollen during your battle with pink eye, you aren't being dramatic!  This MRI of a patient with viral conjunctivitis in his right eye shows there is significant swelling of the soft tissue around the eye's orbit.  The top and bottom eyelids, the lacrimal gland (which rests just under your eyebrow), and the nasolacrimal duct (the eye's drainage system) all show marked inflammation on this imaging.  No wonder viral conjunctivitis feels so miserable.  Due to the significant swelling seen on this imaging, doctors consider treating the symptoms of viral conjunctivitis with steroid eye drops more warranted in patients with significant complaints.

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4. You'll get better (eventually) without treatment.  Viral conjunctivitis infections are typically self-limiting, resolving full within 1-2 weeks.  Your body's immune system fights off the infection just like when you have a common viral cold.  That's why the most common treatments for conjunctivitis involve cool compresses and frequent artificial tear use.  The infection itself is highly contagious, so frequent handwashing and avoiding directly touching others for the first 7 days is the best way to prevent spreading the virus to family, friends, coworkers, and your other eye.  Because the symptoms can be so severe (see Bob Costas' epic pink eye debacle from the 2014 Winter Olympics as a case in point), many doctors do offer treatment with topical steroids to reduce the swelling and redness, but these drops won't fight the viral infection or make you less contagious in any way.  Additionally, treating viral infections with antibiotics won't help treat the virus you have, but some doctors will prescribe these if they feel your risk for a secondary bacterial infection is high (lowered immune system, patients at risk, etc). 

Many people wondered why Bob Costas didn't get treatment for his eye infection and missed a good amount of his Olympic broadcasts.  Viral infections have no anti-viral treatment so he was forced to wait it out, but perhaps steroid eye drops would have made him more comfortable during the ordeal.  via

5. Not all viruses are created equal, and not all are self-resolving.  In 1.8 to 2.3% of acute red eye infections, the underlying culprit is the highly dangerous herpes simplex virus.  This type of viral infection does necessitate prompt treatment -- permanent corneal damage and blindness is a possibility.  So how do you know if you have the more common, self-limiting viral conjunctivitis that just needs palliative treatment, or this much more aggressive viral infection?  This is where a trip to your eye doctor is essential! Herpetic infections typically have tell-tale corneal and eyelid lesions that will allow your doctor to prescribe the proper medication.  If you have scabby, crusty lesions along your eyelid or face or blurry vision and a concurrent red eye, you need to see a doctor immediately!!

Herpes Simplex Keratitis has tell-tale corneal dendritic lesions that your eye doctor can find when they use sodium fluorescein dye staining.   Just one of the tools that your eye doctor has the probably won't be found at urgent care. via