Left untreated, diphtheria can lead to:

  • Breathing problems. Diphtheria-causing bacteria may produce a toxin. This toxin damages tissue in the immediate area of infection — usually, the nose and throat. At that site, the infection produces a tough, gray-colored membrane composed of dead cells, bacteria and other substances. This membrane can obstruct breathing.
  • Heart damage. The diphtheria toxin may spread through your bloodstream and damage other tissues in your body, such as your heart muscle, causing such complications as inflammation of the heart muscle (myocarditis). Heart damage from myocarditis may be slight, showing up as minor abnormalities on an electrocardiogram, or severe, leading to congestive heart failure and sudden death.
  • Nerve damage. The toxin can also cause nerve damage. Typical targets are nerves to the throat, where poor nerve conduction may cause difficulty swallowing. Nerves to the arms and legs also may become inflamed, causing muscle weakness. If C. diphtheria toxin damages the nerves that help control muscles used in breathing, these muscles may become paralyzed. Respiration may then become impossible without a respirator or another device to assist with breathing.

With treatment, most people with diphtheria survive these complications, but recovery is often slow. Diphtheria is fatal in as many as 3 percent of those who get the disease.

Mar. 27, 2014