Signs and Symptoms

Diphtheria can infect the respiratory tract (parts of the body involved in breathing) and skin. Symptoms of diphtheria depend on the body part that is affected. People who are exposed to diphtheria usually start having symptoms in 2–5 days if they get sick. If a doctor thinks you have respiratory diphtheria, they will have you start treatment right away.

Photo of child with swollen neck due to diphtheria infection

A child with a swollen neck due to diphtheria infection.

Respiratory diphtheria

The bacteria most commonly infect the respiratory system, which includes parts of the body involved in breathing. When the bacteria get into and attach to the lining of the respiratory system, it can cause:

  • Weakness
  • Sore throat
  • Mild fever
  • Swollen glands in the neck

The bacteria make a toxin that kills 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. Medical experts call this thick, gray coating a “pseudomembrane.” It can cover tissues in the nose, tonsils, voice box, and throat, making it very hard to breathe and swallow.

If the toxin gets into the blood stream, it can cause heart, nerve, and kidney damage.

Diphtheria skin infection

The bacteria can also infect the skin, causing open sores or ulcers. However, diphtheria skin infections rarely result in severe disease.