Conjunctivitis and Kids

BY WILLIAM TOWNSEND, O.D.
JAN. 1996

The management of an ocular condition is usually the same for adults and children, but there are exceptions. The most common causative organisms in pediatric bacterial conjunctivitis are Hemophilus influenza, a gram-negative organism, and Strep pneumonia (pneumoccoccus), a gram-positive organism. Adenovirus predominates in older children.

DIAGNOSIS

Although we rarely culture bacterial conjunctivitis in adults because the added expense and effort rarely justify the results, it may be a good idea to culture pediatric cases. If you have access to a microscope, a gram stain can yield valuable information. Conjunctival scrapings that show a predominance of polymorphonuclear leukocytes indicate a bacterial infection. When mononuclear cells are predominant, the causative agent is most likely a virus.

Children may not show typical signs of bacterial disease. In one study for example, 9 percent of Hemophilus cases and 17 percent of Strep cases did not show a purulent exudate. Interestingly, 45 percent of cases that cultured positive for Adenovirus but negative for any bacteria showed a purulent exudate, thus demonstrating that every purulent conjunctivitis is not bacterial.

Preauricular adenopathy is also a good indicator that the disease is viral. Although it's usually accurate to say that papillae indicate bacterial disease and follicles suggest a viral etiology, it can be misleading. Papillae are a general response to inflammation and may be present in viral or bacterial disease. Most children develop follicular hypertrophy anyway, which could confuse the diagnostic picture and give the mistaken impression of viral disease.

TREATMENT

The treatment of pediatric bacterial conjunctivitis is fairly straightforward. A combination of neomycin, polymyxin B, and gramicidin has been very effective, but unfortunately, some patients exhibit hypersensitivity to neomycin. Aminoglycosides continue to be our first choice for adult conjunctivitis, but not so for children since we've witnessed cases in which Hemophilus was resistant to aminoglycosides. Fluoroquinolones (Ciloxan, Chibroxin) are also approved for children, but may not eradicate gram-positive organisms as well as other medications.

For most of our pediatric conjunctivitis cases, we prefer Polytrim, a combination drug that includes trimethoprim and polymyxin B. Trimethoprim, which interferes with folic acid synthesis, is also active against gram-negative species such as Hemophilus and Pseudomonas. Polymyxin B disrupts the phospholipid portion of the bacterial cell wall. It's particularly effective against the gram-negative species mentioned earlier and used topically, has low toxicity and few side effects.

Adenovirus presents as a unilateral conjunctivitis that soon spreads to the contralateral eye. Preauricular adenopathy and follicles are classic signs that suggest Adenovirus. Usually, the discharge is mucoid or watery, but in severe cases, a purulent discharge may convince the examining doctor that the condition is bilateral. The onset of coarse keratitis and subepithelial infiltrates, usually about one week after the onset of symptoms, reveals the true nature of the disease. Although the condition is self-limiting, patients are frequently miserable, complaining of photophobia and a foreign body sensation. Artificial tears alleviate mild symptoms of pediatric EKC. Parents should be advised of the highly infectious nature of this disease to take appropriate measures to prevent spreading it to other family members. The patient should be kept out of school for at least one week after the onset of symptoms.

If a patient with viral or bacterial conjunctivitis is extremely uncomfortable, we add an NSAID such as Voltaren or Acular to reduce inflammation. Unlike corticosteroids, these medications don't reduce the body's natural immune response, but they do make the patient much more comfortable.

And one day, your pediatric conjunctivitis patients may become successful contact lens wearers. CLS

Dr. Townsend is in private practice in Canyon, Texas, and is a consultant at the Amarillo VA Medical Center.