Conjunctivitis, more popularly known as pink eye, occurs when there is an inflammation of the outer layer of the eye as well as the internal layer of the eyelid. Conjunctivitis is due usually to an infection (either bacterial or viral). It can also occur from an allergic reaction. Conjunctivitis can be categorized into two types. One type of conjunctivitis is due to a specific cause, while the other is due to how involved the inflammation is. Relating to cause, there are various types of conjunctivitis. For example, there is viral conjunctivitis (caused by a virus), chemical conjunctivitis (caused by a chemical reaction to the eye), allergic conjunctivitis (caused by allergies), and bacterial conjunctivitis (caused by a bacteria). Regarding the extent of involvement, there are two main forms. One form is called Blepharoconjunctivitis, which is a mix between conjunctivitis and an inflammation of the eye, termed blepharitis. The second form is called Keratoconjunctivitis, and is characterized by conjunctivitis and an inflammation of the cornea known as keratitis.
In most cases, conjunctivitis is caused by a viral infection. However, oftentimes allergic reactions (such as from dust or pet dander), bacteria, chemical irritations (such as chlorine in a swimming pool or polluted air such as smog), as well as general dryness to the eyes can also cause a person to contract conjunctivitis. The virus and bacteria forms are highly contagious, and passed along via human to human (it may also be passed via polluted water or contaminated surfaces). Regarding the viral form of conjunctivitis, the root source is the virus called adenovirus. There is also a form of viral conjunctivitis that is caused by the herpes virus, which can be quite serious and should be treated immediately with drugs. Another viral form is called acute hemorrhagic, and is also very contagious, with its root source being either one of two enteroviuses: Enterovirus 70 or Coxsackievirus A24. Both of these viral forms have spread globally and have been responsible for many epidemics over the past decades. Regarding the other highly contagious forms, the bacterial forms, the most common of these are the Staphylococcus and Streptococcus forms, with the Staphylococcus form being responsible for the more long-term cases of bacterial conjunctivitis (lasting for more than 3 weeks).
When it comes to conjunctivitis in general, there exists common symptoms to all, such as red eyes, a swelling of the area of the eye called the conjunctiva, and watery eyes. However, regarding specific forms (viral, bacterial, etc.) symptoms can be form-specific. Thus, for example, when it comes to the viral form, signs include burning, itchy eyes, and a sensitivity to light. With the viral form, the infection may start in only one of the eyes, and then quite often spread to the other eye. Other signs of the viral form, is of course a pink coloration on the eye. Also, the viral form is often associated with respiratory infections and common colds. Thus associated symptoms may include runny nose, sinus congestion, coughing, and a sore throat. Regarding the bacterial form of conjunctivitis, usually there is a sudden and rapid progression of redness of the eye, the eyelid swells, and a mucus will discharge from the eye. These symptoms first appear in one of the eyes, and in about 3 days it will move to the other eye as well. The mucus, pus-like discharge will cause a sensation of grittiness in the eye, with the discharge itself being greyish-yellowish in color, often causing the eyelids to stick together, and crust over after the person awakens from sleep.
When it comes to treatment and management of conjunctivitis, once again options will depend upon the form of the conjunctivitis (viral, bacterial, allergy, chemical). However, in most cases (65%), the conjunctivitis will clear up on its own within about 3 days. In more serious cases though, treatment will be needed. Thus for the viral form, an iodine solution to the eye, followed by eye drops is the prescribed method. For the bacterial form, antibiotics are given along with eye drops and even ointment. It should be noted however, that there is little observed difference in speed of recovery between people treated with antibiotics and without (3.3 days vs 4.8 days, respectively). Also, the number of cases of conjunctivitis stemming from sexually transmitted diseases is rising. When such cases are present, immediate medical attention should be sought, and strong antibiotics will be given. For the allergic form, certain anti-inflammatory drugs and antihistamines are prescribed, as well as steroid eye drops. Also, often splashing cold water into the eyes will alleviate the discomfort associated with this allergic form. Finally, for the chemical form of conjunctivitis, a simple saline solution will work fine. Although if the chemical reaction with the eye involves a chemical that can cause burns (such as alkali burns), medical attention is immediately required, as scarring on the eye, and even blindness, could occur.