Diphtheria (dif-THEER-e-uh) is a serious bacterial infection usually affecting the mucous membranes of your nose and throat. Diphtheria typically causes a sore throat, fever, swollen glands and weakness. The poison destroys healthy tissues in the respiratory system. Within two to three days, the dead tissue forms a thick, gray coating that can build up in the throat or nose. This thick gray coating is called a “pseudomembrane.” It can cover tissues in the nose, tonsils, voice box, and throat, making it very hard to breathe and swallow. The poison may also get into the blood stream and cause damage to the heart, kidneys, and nerves.
What Causes Diphtheria?
The condition is typically spread through person-to-person contact or through contact with objects that have the bacteria on them, such as a cup or used tissue. You may also get diphtheria if you’re around an infected person when they sneeze, cough, or blow their nose. Even if an infected person doesn’t show any signs or symptoms of diphtheria, they’re still able to transmit the bacterial infection for up to six weeks after the initial infection.
- A thick, gray membrane covering your throat and tonsils
- A sore throat and hoarseness
- Swollen glands (enlarged lymph nodes) in your neck
- Difficulty breathing or rapid breathing
- Nasal discharge
- Fever and chills
In some people, infection with diphtheria-causing bacteria causes only a mild illness — or no obvious signs and symptoms at all. Infected people who remain unaware of their illness are known as carriers of diphtheria, because they can spread the infection without being sick themselves.
Skin (cutaneous) diphtheria
A second type of diphtheria can affect the skin, causing the typical pain, redness and swelling associated with other bacterial skin infections. Ulcers covered by a gray membrane also may develop in cutaneous diphtheria.
It is more common in tropical climates, particularly among people with poor hygiene who live in crowded conditions.
The bacterium Corynebacterium diphtheriae causes diphtheria. Usually C. diphtheriae multiplies on or near the surface of the mucous membranes of the throat. C. diphtheriae spreads via three routes:
- Airborne droplets. When an infected person’s sneeze or cough releases a mist of contaminated droplets, people nearby may inhale C. diphtheriae. Diphtheria spreads efficiently this way, particularly in crowded conditions.
- Contaminated personal items. People occasionally catch diphtheria from handling an infected person’s used tissues, drinking from the infected person’s unwashed glass or coming into similarly close contact with other items on which bacteria-laden secretions may be deposited.
- Contaminated household items. In rare cases, diphtheria spreads on shared household items, such as towels or toys. You can also come in contact with diphtheria-causing bacteria by touching an infected wound.
People who have been infected by the diphtheria bacteria and who haven’t been treated can infect non-immune people for up to six weeks — even if they don’t show any symptoms.
How Is Diphtheria Diagnosed?
Your doctor will likely perform a physical exam to check for swollen lymph nodes. They’ll also ask you about your medical history and the symptoms you’ve been having.
Your doctor may believe that you have diphtheria if they see a gray coating on your throat or tonsils. To confirm the diagnosis, they’ll take a sample of the affected tissue and send it to a laboratory for testing. A throat culture may also be taken if your doctor suspects diphtheria of the skin.
Diphtheria is a serious illness. Doctors treat it immediately and aggressively with these medications:
- An antitoxin. If doctors suspect diphtheria, the infected child or adult receives an antitoxin. The antitoxin, injected into a vein or muscle, neutralizes the diphtheria toxin already circulating in the body.Before giving an antitoxin, doctors may perform skin allergy tests to make sure that the infected person doesn’t have an allergy to the antitoxin. People who are allergic must first be desensitized to the antitoxin. Doctors accomplish this by initially giving small doses of the antitoxin and then gradually increasing the dosage.
- Antibiotics. Diphtheria is also treated with antibiotics, such as penicillin or erythromycin. Antibiotics help kill bacteria in the body, clearing up infections. Antibiotics reduce to just a few days the length of time that a person with diphtheria is contagious.Children and adults who have diphtheria often need to be in the hospital for treatment. They may be isolated in an intensive care unit because diphtheria can spread easily to anyone not immunized against the disease.Doctors may remove some of the thick, gray covering in the throat if the covering is obstructing breathing.
If you’ve been exposed to a person infected with diphtheria, see a doctor for testing and possible treatment. Your doctor may give you a prescription for antibiotics to help prevent you from developing the disease. You may also need a booster dose of the diphtheria vaccine.
Doctors treat people who are found to be carriers of diphtheria with antibiotics to clear their systems of the bacteria, as well.