Diphtheria

Definition

Diphtheria is an acute infectious disease caused by the bacteria Corynebacterium diphtheriae.

Causes, incidence, and risk factors

Diphtheria spreads through respiratory droplets (such as those produced by a cough or sneeze) of an infected person or someone who carries the bacteria but has no symptoms. Diphtheria can also be spread by contaminated objects or foods (such as contaminated milk).

The bacteria most commonly infects the nose and throat. The throat infection causes a gray to black, tough, fiber-like covering, which can block the airways. In some cases, diphtheria may first infect the skin, producing skin lesions.

Once infected, dangerous substances produced by the bacteria can spread through your bloodstream to other organs, such as the heart, and cause significant damage.

Because of widespread and routine childhood DPT immunizations, diphtheria is now rare in many parts of the world. There are fewer than five cases of diphtheria a year in the United States.

Risk factors include crowded environments, poor hygiene, and lack of immunization.

Symptoms

Symptoms usually occur 2 to 5 days after you have come in contact with the bacteria.

• Bluish coloration of the skin
• Bloody, watery drainage from nose
• Breathing problems
  • Difficulty breathing
  • No breathing
  • Rapid breathing
  • Stridor
• Chills
• Croup-like (barking) cough
• Drooling (suggests airway blockage is about to occur)
• Fever
• Hoarseness
• Painful swallowing
• Skin lesions (usually seen in tropical areas)
• Sore throat (may range from mild to severe)

Note: There may be no symptoms.

Signs and tests

The health care provider will perform a physical exam and look inside your mouth. This may reveal a gray to black covering (pseudomembrane) in the throat, enlarged lymph glands, and swelling of the neck or larynx.

Tests used may include:

• Gram stain or throat culture to identify Corynebacterium diphtheriae
• Electrocardiogram (ECG)