What is diphtheria?

Diphtheria is an illness caused by bacteria. There are two types:

• Respiratory diphtheria. This type affects the throat, nose, and tonsils.

• Skin (cutaneous) diphtheria. This type affects the skin.

It was a common childhood disease in the past. A vaccine against diphtheria has now made it very rare in the U.S. and other developed countries.

What causes diphtheria?

The illness is caused by bacteria called Corynebacterium diphtheria.

These bacteria can enter the body through the nose and mouth. This causes respiratory diphtheria. It's spread from person to person by breathing in droplets that contain diphtheria bacteria when an infected person coughs or sneezes.

The bacteria can also enter through a break in the skin. This can cause skin diphtheria. After being exposed to the bacteria, it often takes 2 to 4 days for symptoms to start.

What are the symptoms of diphtheria?

Symptoms may be a bit different for each person. The most common symptoms are below.

Respiratory diphtheria. When a person is infected with diphtheria, the bacteria often grow in the throat. A membrane may form over the throat and tonsils. This causes a sore throat. Other symptoms may include:

• Trouble breathing because of the membrane

• Husky voice

• Enlarged lymph glands

• Fast heart rate

• A harsh or high-pitched breathing sound (stridor) due to narrowing of the upper airways

• Nasal drainage

• Swelling of the roof of the mouth

• Sore throat

• Low-grade fever

• A general feeling of discomfort (malaise)

In some cases, the membrane blocks breathing. A person may die if this happens. Other complications are caused by the diphtheria poison (toxin) released in the blood. This leads to heart or kidney failure and nerve problems.

Skin (cutaneous) diphtheria. With this type of diphtheria, the symptoms are often milder. They may include yellow spots or sores on the skin. These spots or sores may look like impetigo.

The symptoms of diphtheria may look like other health conditions. Always talk with your healthcare provider for a diagnosis.

How is diphtheria diagnosed?

Your healthcare provider will look for common symptoms. A diagnosis is confirmed by taking a throat swab to test for the bacteria. If the skin is affected, a sample from a skin sore can also be taken.

How is diphtheria treated?

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.

If your healthcare provider thinks you have diphtheria, treatment will be started right away. Diphtheria is a very serious illness. Even with treatment, about 1 out of 10 people will die.

Antibiotics often work well to treat respiratory diphtheria before it releases toxins in the blood. An antitoxin can be given along with the antibiotic. In some cases, surgery may be done to put a breathing tube into the windpipe (tracheostomy). This is needed for severe breathing problems.

A person with diphtheria will often be kept in isolation until they are not contagious. This is often about 48 hours after starting antibiotics. When the course of antibiotics is done, you will have tests to make sure that the bacteria are not in your body anymore.

Can diphtheria be prevented?

In their first year of life, children in the U.S. are given a triple vaccine that includes a vaccine for diphtheria, with several booster doses given later in childhood. This has made cases of diphtheria very rare in the U.S. But diphtheria still occurs in developing countries. So the vaccine is still needed in case of contact with a person with diphtheria (a carrier) who is visiting from another country. The vaccine is also needed for travel to an area where diphtheria is active.

The CDC advises that children need 5 DTaP shots. A DTaP shot is a combination vaccine that protects against three diseases. It protects against diphtheria, tetanus, and pertussis. The first three shots are given at ages 2, 4, and 6 months. The fourth shot is given between ages 15 and 18 months. The fifth shot is given when a child enters school at ages 4 to 6 years. At their regular checkups, preteens ages 11 or 12 should get a dose of Tdap. The Tdap booster protects against tetanus, diphtheria, and pertussis.

Adults who did not get a Tdap booster as a preteen or teen should get a dose of Tdap. All adults should get a tetanus-diphtheria (Td or Tdap) booster every 10 years. But it can be given before the 10-year mark. Always talk with your healthcare provider for advice.

The CDC advises that pregnant women get a Tdap vaccine between 27 and 36 weeks of each pregnancy. This is so that antibodies can go to the baby before birth. Always talk with your healthcare provider for advice.

Key points about diphtheria

• Diphtheria is an illness caused by bacteria. There are two types. The respiratory form affects the throat, nose, and tonsils. Skin diphtheria affects the skin.

• It's spread by respiratory secretions, and by breathing in infected droplets when an infected person coughs or sneezes. It can also be spread by touching a contaminated object.

• Symptoms of the respiratory form include trouble breathing, fast heart rate, and sore throat. The symptoms of skin diphtheria are often milder. They may include yellow spots or sores on the skin.

• Antibiotics are used to treat respiratory diphtheria before it releases toxins in the blood. An antitoxin can be given at the same time. Sometimes a tracheostomy is needed for severe breathing problems.

• If your healthcare provider thinks you have diphtheria, treatment will be started right away. Diphtheria is a very serious illness. Even with treatment, about 1 out of 10 people will die.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your provider if you have questions.