Diphtheria: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Diphtheria?
Diphtheria is usually treated by an infectious disease doctor, a doctor who treats illnesses caused by germs. You may need to stay in the hospital while getting a medicine called an antitoxin. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is diphtheria?
Diphtheria is a serious disease caused by a toxin, or poison, made by some kinds of bacteria called Corynebacterium diphtheriae. The toxin, not the germ itself, causes the serious effects.
The most serious type is respiratory diphtheria, an infection of the nose and throat. The bacteria can also infect the skin. This is skin diphtheria.
Symptoms
Symptoms usually start 2 to 5 days after the bacteria enter the body, and can include:
- Fever and chills.
- Sore throat and a rough voice (hoarseness).
- Painful swallowing.
- A barking cough, like croup.
- Bloody, watery drainage from the nose.
- Breathing problems, including hard breathing, fast breathing, and a high-pitched breathing sound.
- Drooling, which suggests the airway is about to be blocked.
- Bluish skin color.
In the throat, the infection causes a gray to black, tough covering that can block the airways. Skin infections cause skin sores, usually seen in tropical areas. Sometimes there are no symptoms.
The most common complication is swelling of the heart muscle. The nervous system is also often affected, which may cause temporary paralysis.
Causes and who gets it
The bacteria most often spread by coughing or sneezing. Other people can get infected if they breathe in the tiny droplets. Touching open sores or ulcers caused by the bacteria can also spread it.
The droplets can come from a sick person, or from a carrier with no symptoms. The toxins spread through your blood to other organs, such as the heart and brain, and cause damage.
Crowded places, poor hygiene, and no vaccines raise the risk. Nearly all cases in the United States are linked to travel to an affected area in another country.
Vaccines are the best protection. CDC recommends diphtheria vaccination for everyone. The shots are given in childhood, and adults need a booster every 10 years.
How doctors diagnose it
Providers usually decide if a person has it by looking for common signs and symptoms. If they suspect respiratory diphtheria, they start treatment right away without waiting for test results.
The provider looks inside your mouth. This may show a gray to black covering in the throat. It may also show enlarged lymph glands and swelling of the neck or vocal cords.
Testing involves swabbing a skin wound or the back of the throat and nose. If bacteria grow, a lab must then test for the toxin. This is the only way to be sure it is diphtheria. Tests may also include a heart test called an ECG.
Treatment
Respiratory diphtheria is usually treated with antitoxin and antibiotics. The antitoxin stops the toxin from causing more damage. Antibiotics kill and get rid of the bacteria.
The antitoxin is given as a shot into a muscle or through an IV, which is a line into a vein. Some people have an allergic reaction to the antitoxin. Skin infections are generally treated with antibiotics only. In the hospital, other treatments may include:
- Fluids through an IV.
- Oxygen.
- Bed rest.
- Heart monitoring.
- A breathing tube and care to clear airway blockages.
After the antibiotics are finished, testing is repeated to make sure the bacteria are completely gone. People with no symptoms who carry the bacteria should also get antibiotics.
Recovery from the illness is slow. People may die, especially when the disease affects the heart.
When to see a doctor
Contact your provider right away if you have been in contact with a person who has diphtheria. Close contacts should get antibiotics so they do not get sick.
Call 911 or go to the emergency room if you or your child has serious trouble breathing or bluish skin. Drooling is also a warning sign that the airway may soon be blocked.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. A direct primary care doctor can check your symptoms and vaccine record. They can also send you to the right specialist or hospital.
Common questions
Can diphtheria be prevented?
Yes. The best way to prevent diphtheria is to get vaccinated. The vaccines work well but cannot prevent all cases.
Is diphtheria dangerous?
Yes. It is a serious disease. The toxin kills healthy tissues and can cause many serious health problems.
Is diphtheria common in the United States?
No. Diphtheria is a rare disease. Nearly all cases here are linked to travel to an affected area abroad.
How soon do symptoms start after exposure?
Symptoms usually start 2 to 5 days after the bacteria enter the body.
How does diphtheria spread?
It most often spreads by coughing or sneezing.
Sources
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
