Conjunctivitis: Red Eye or Pink Eye
What Is Conjunctivitis?
The conjunctiva is the outer, relatively clear, cellophane like covering of the front white part of the eye. When the conjunctiva becomes red or inflamed, the medical term for this condition is conjunctivitis. The lay public commonly calls conjunctivitis “pink eye.” However, conjunctivitis or “pink eye” is not one disorder, but it can have many different causes that have completely different treatments. Many different eye conditions can cause the eye to become pink or red.
What Causes Conjunctivitis?
Infections are a leading cause of conjunctivitis, but there are several different infectious agents that can cause conjunctivitis. Incorrect treatment will not improve the red or pink eye. The most commonly seen forms of conjunctivitis include:
- Bacterial Conjunctivitis
This often caused by staph or strep bacteria. Your child may have the same bacteria in the throat or nose. Usually, a significant yellow or mucus discharge is present. Frequent instillations of antibiotic eye drops will usually significantly improve the condition in a few days. If antibiotic drops are not helpful within 3 to 4 days, your child may have another condition.
- Viral Conjunctivitis
This is caused by a viral infection of the conjunctiva. Again, your child may have the same viral infection in the nose, throat or respiratory passages that cause a cough, runny nose or sore throat. A clear or mucus discharge may be present. Antibiotic eye drops will NOT be helpful for antibiotics are only effective against bacteria and are not effective in viral infections. After a careful eye exam, steroid eye drops can sometimes be used to decrease the inflammation in the eye. However, steroid eye drops must be used with great care as steroids can worsen some eye conditions (such as herpes simplex: see below) and can cause cataracts and glaucoma if used for an extended period of time.
This is a common and under diagnosed condition in which the oily glands of the eyelid become obstructed and do not function properly, often resulting in crusting of the eyelids especially in the morning. The improperly functioning oily glands are very susceptible to bacterial infection that can occur repeatedly unless the underlying oily gland problem is properly diagnosed and treated. Treatment of blepharitis involves eyelid scrubs, warm compresses and antibiotic ointment at bedtime as well as antibiotic eye drops for secondary bacterial conjunctivitis.
- Herpes Simplex Conjunctivitis and Keratitis
This is a relatively common and often overlooked cause of “red eye.” Herpes simplex (a particular type of virus) infections of the front of the eye (the cornea) can result in conjunctivitis. This can superficially look just like a common viral or bacterial infection of the eye. However, careful examination by an eye professional will detect a defect of the front lining of the eye. A special stain called flourescein is the best tool for an eye professional to detect herpes simplex infections.
Herpes simplex may be the result of Type 1 or Type 2. At one time type I infections primarily caused “cold sores” or fever blisters, and type 2 caused genital herpes (a venereal infection). Today, Type I or Type 2 both can be the cause of either genital herpes or ocular herpes infections. Most often, herpes simplex eye infections can be effectively treated with specific anti-viral eye drops or oral medications specific for herpes simplex. Regular antibiotic eye drops are not effective against herpes simplex infections and steroid eye drops can cause significant damage to eyes with this type infection.
- Foreign Bodies on the Eye
Very often a foreign object of various kinds, such as a piece of wood, an insect fragment or piece of metal can become lodged on the surface of the eye. This foreign material will cause the eye to become red and inflamed. One will appear to have “pink eye”. Unfortunately, many times the foreign body is small and unseen unless the eye is examined with a special slit lamp microscope. Usually a child will experience some degree of pain and light sensitivity. Treatment with antibiotic eye drops will not cure the problem. The foreign body must be removed or the eye will continue to stay red. A serious infection in the front of the child’s eye can result without foreign body removal.
- Allergic Conjunctivitis
There are many types of allergic conjunctivitis but all have one thing in common: something comes into contact with the ocular surface that makes the eye red or inflamed and looks just like “pink eye.” Some types, like hay fever, cause a very itchy eye with a watery discharge. Other types of allergies can produce ongoing redness of the eye; still, others can produce a mucous discharge and even result in scarring of the front of the eye.
Pollen or other plant matter is a common cause. Children may be allergic to cats, feather pillows or tiny microorganisms that live in the air. Children with other allergic conditions like allergic rhinitis (frequent nose runs) or atopic dermatitis (a skin condition) are much more prone to allergic conjunctivitis.
Antibiotics are not helpful with pure allergies. In fact, children are often allergic to the antibiotic eye drops; therefore, while using antibiotic drops the condition may actually appear to worsen as the eye become redder and redder. On the other hand, children with allergic conjunctivitis are more prone to develop secondary bacterial infections, signaled by an increase in a yellow discharge. This secondary infection may well require antibiotic eye drops that should be discontinued when the infection is controlled.
There are many different eye drops used to treat allergic conjunctivitis. Some, like Naphcon-A, can be purchased without a prescription. Other very effective drops, like Patanol or Zaditor, require a prescription but can bring great relief to a child with significant symptoms. More potent eye drops can be used frequently if the condition is an ongoing problem. Oral antihistamines like Zyrtec or Benadryl, are suggested for younger children in which eye drop instillation is very difficult or older children with concurrent allergic rhinitis (nasal involvement).
The diagnosis and treatment of a red eye or “pink eye” can be far from simple. If a red eye persists more than 2 or 3 days, or if any significant pain or sensitivity to light is present even on the first day, consultation with a competent eye professional is recommended. Parents may find out their three year old has harbored an insect fragment on the front of the eye for 2-3 weeks or have missed a treatable case of herpes simplex keratitis that can cause permanent blindness. This can cause unnecessary embarrassment and guilt for parents.
Early treatment is the best cure for the many forms of conjunctivitis.