January 30, 2007

The Throat


In anatomy, the throat is the part of the neck anterior to the vertebral column. It consists of the pharynx and larynx.

The throat contains various blood vessels, various pharyngeal muscles, the trachea (windpipe) and the esophagus. The hyoid bone and the Clavicle are the only bones located in the throat of mammals.

Throat Related Problems
There are diseases that seems to affect the throat. These include


Epiglottitis is a life-threatening condition that occurs when the epiglottis — a small cartilage "lid" that covers the windpipe — swells, blocking the flow of air into the lungs.

A number of factors can cause the epiglottis to swell, including burns from hot liquids, a direct injury to the throat, and various viral and bacterial infections. The most common cause of epiglottitis is infection with Haemophilus influenzae type b (Hib), the same bacterium that causes pneumonia and meningitis.

Routine Hib vaccination for infants has made epiglottitis an uncommon condition, but it remains a valid concern. If you suspect that you or someone in your family has epiglottitis, seek emergency help immediately. Prompt treatment can prevent life-threatening complications

Signs and symptoms
Epiglottitis caused by Hib infection usually begins with a fever and severe sore throat. Other signs and symptoms may develop within a matter of hours, including:

Difficult and painful swallowing
Drooling due to severe pain when swallowing
A muffled voice
Harsh, raspy breathing
Difficulty breathing
Blue skin or lips

Your voice box (larynx) is a framework of cartilage, muscle and mucous membrane that forms the entrance to your windpipe (trachea), the tube that connects your mouth and throat to your lungs. The epiglottis is a small, movable "lid" just above the larynx that prevents food and drink from entering your windpipe.

It does this by dropping down when you swallow, effectively sealing off the larynx. That's why you can't swallow and breathe at the same time. When you're not eating or drinking, the epiglottis is slightly lifted so that air can flow freely into your lungs. But if the epiglottis becomes swollen — either from infection or injury — the airway narrows and may become completely blocked.

The most common cause of swelling and inflammation of the epiglottis and surrounding tissues is infection with Haemophilus influenzae type b (Hib) bacteria. Hib isn't the germ that causes the flu, but it's responsible for other serious conditions — including respiratory tract infections and meningitis.

Hib spreads through infected droplets coughed or sneezed into the air. It's possible to harbor Hib in your nose and throat without becoming sick — though you still have the potential to spread the bacteria to others.

Other bacteria and viruses also can cause inflammation of the epiglottis, including:

Streptococcus pneumoniae (pneumococcus), the most common cause of meningitis
Streptococcus A, B and C, a group of bacteria that cause diseases ranging from strep throat to blood infections

Candida albicans, the fungus responsible for vaginal yeast infections, diaper rash and oral thrush
Varicella zoster, the virus responsible for chickenpox and shingles

Physical injury, such as a direct blow to the throat, can cause epiglottitis. So can scald burns to your face or burns from drinking very hot liquids.

You also may develop signs and symptoms similar to those of epiglottitis if you:

Swallow a chemical that burns your throat
Swallow a foreign object
Smoke drugs, such as crack cocaine and heroin

Risk factors
For most of the 20th century, epiglottitis was more common in children than in adults — especially children ages 2 to 7. But since routine childhood Hib immunizations began in 1985, the number of children with epiglottitis has dropped dramatically. Today the condition affects about one of every 100,000 adults a year and even fewer children.

It's difficult to predict who might develop epiglottitis, but certain factors increase the risk.

Sex. Epiglottitis affects more men than women.

Race. In the United States, blacks and Hispanics tend to develop epiglottitis more frequently than do whites. A difference in access to medical care — including childhood immunizations — may be responsible for the higher rates of epiglottitis in underserved populations.

Crowded conditions. Hib bacteria spread rapidly when people are in close contact. Hib infections are most prevalent in child care centers, but they also spread quickly in schools, in offices and within households.

Weak immune system. If your immune system has been weakened by illness or medication, you're more susceptible to the viral and bacterial infections that may cause epiglottitis.

When to seek medical advice
Epiglottitis is a medical emergency. If someone you know suddenly has trouble breathing and swallowing, call your local emergency number or go to the nearest hospital emergency department. Don't try to examine the person's throat yourself. This can make matters worse.

Screening and diagnosis
If the medical team suspects epiglottitis, no diagnostic tests will be done until your airways are open and it's certain you're receiving enough oxygen.

Once your condition is stable, the doctor may examine your throat using a flexible fiber-optic tube. A local anesthetic can help relieve any discomfort. Sometimes you may have a chest or neck X-ray as well. Because of the danger of sudden breathing problems, children may have X-rays taken at their bedside rather than in the radiology department — again, only after the airway is protected.

You're also likely to have a blood test and throat culture. For the culture, your epiglottis is wiped with a cotton swab and the tissue sample is checked for Hib.

Epiglottitis can lead to respiratory failure — a life-threatening condition in which the level of oxygen in the blood drops dangerously low or the level of carbon dioxide becomes excessively high.

Pulmonary edema, another life-threatening condition, can develop after airway treatment for epiglottitis. It occurs when the tiny air sacs in the lungs fill with fluid, preventing them from absorbing oxygen.

Sometimes the bacteria that cause epiglottitis cause infections elsewhere in the body, such as pneumonia, meningitis or a blood infection (sepsis).

The first priority in treating epiglottitis is ensuring that you're receiving enough air. You may wear a mask that delivers oxygen to your lungs. Or you may have a breathing tube placed into your windpipe through your nose or mouth. The tube must remain in place until the swelling in your throat has decreased — sometimes up to two or three days.

In extreme cases or if more conservative measures fail, the doctor may create an emergency airway by inserting a needle directly into an area of cartilage in your trachea. This procedure allows air into your lungs while bypassing the larynx. The needle is removed as soon as the airway is open.

If your epiglottitis is related to an infection, you'll receive intravenous antibiotics once you're breathing freely. Until your doctor knows the results of your blood and tissue cultures, you're likely to be treated with a broad-spectrum drug. You may receive a different antibiotic later, depending on what's causing your epiglottitis.

Immunization with the Hib vaccine is the most effective way to prevent epiglottitis in children younger than age 5. In the United States, children usually receive the vaccine in four doses: at ages 2 months, 4 months, 6 months and 12 to 15 months.

The Hib vaccine is generally not given to children older than age 5 or to adults because they're less likely to develop Hib infection. But the Centers for Disease Control and Prevention recommends the vaccine for older children and adults whose immune systems have been weakened by:

Sickle cell disease
Spleen removal
Medications to prevent rejection of organ or bone marrow transplants

The most common side effects of the Hib vaccine include redness, warmth or swelling at the injection site, and a fever. Rarely, a serious allergic reaction may cause difficulty breathing, wheezing, hives, weakness, a rapid heartbeat or dizziness within minutes or a few hours after the shot. If you have an allergic reaction to the vaccine, seek medical help immediately.

Of course, the Hib vaccine doesn't offer guarantees. Immunized children have been known to develop epiglottitis — and many other germs can cause epiglottitis, too. That's where common-sense precautions come in. Don't share personal items. Wash your hands frequently. If soap and water aren't available, use an alcohol-based hand sanitizer.

Adapted from: Mayo Foundation for Medical Education and Research