Conjunctivitis is infection of the outer membrane of the eyeball and the inner eyelid by viruses or bacteria. Otherwise known as “pink eye” due to its characteristic redness, it leaves the eyes feeling itchy, gritty, and often causes a crust of discharge to form on the eyelashes at night. Copious tearing occurs with exudate that is high in protein and LDH.

Conjunctivitis is very contagious and is normally transmitted through contaminated fingers coming in contact with mucous membranes. It can also be transmitted via swimming pools and personal items that contact fingers or faces. Children are affected more than adults. Washing hands and avoiding touching mucus membranes around the face helps to prevent infection.

The most common microbial agent that causes conjunctivitis is the adenovirus. There is generally less exudate and more mild symptoms with viral conjunctivitis than with bacterial conjunctivitis. There is no specific treatment for viral conjunctivitis. The symptoms tend to last for several days or up to two weeks.

Bacterial conjunctivitis is less common than viral and is usually caused by Staphylococcus or Streptococcus bacteria, or Haemophilus influenzae. Pathogens that cause bacterial conjunctivitis are similar to those that cause middle ear infections. The inflamed conjunctiva is generally more irritated and painful than with viral infections. The eye drainage associated with bacterial conjunctivitis is sticky and yellow/green with excoriation/abrasion of the lid margins. The infection typically lasts 10-14 days without antibiotics, but only 1-3 days with antibiotics. Antibiotics are generally delivered via ophthalmic eye drops or ointments.

Ophthalmia neonatorum (ON or neonatal conjunctivitis) occurs when a baby’s eyes become contaminated with Neisseria or Chlamydia while exiting the vagina during birth. Due to this increased risk of infection and potential blindness, erythromycin ointment, or some other antibiotic eye drop is routinely applied to newborn’s eyes to prevent ON. Most hospitals are required by state law to apply these antibiotic drops to prevent possible vision loss in newborns.

The conjunctiva can also become irritated and inflamed from caustic chemicals or allergic reactions. For chemical exposure, treatment would involve cleansing the eyes and avoidance of the chemicals in the future. Treatment for allergic conjunctivitis involves the normal array of allergy medications.

Individuals who wear contacts should avoid wearing them until all conjunctivitis symptoms have cleared up.