Diphtheria - Causes, Symptoms, and Treatment

An Overview of Diphtheria:

• A predominant bacterial infection causes it in underdeveloped countries due to limited healthcare and vaccination options.

• Notable symptoms include sore throat, malaise (tiredness), fever, swollen lymph nodes, and a gray, thick pseudomembrane formation in the throat.

• The sore throat and pseudomembrane, along with the results of a bacterial culture, play a significant role in the diagnosis.

• Vaccination plays a vital role in the prevention of this infection.

• The infection is often eliminated by administering antibiotics and, in worst-case scenarios, hospitalizing the patients.

What Is Diphtheria?

Diphtheria is a contagious, sometimes fatal infection of the nose, throat, caused by Corynebacterium diphtheriae. These bacteria release a potent toxin (poison) that causes damage to the kidneys, heart, and nervous system. In advanced stages, it leads to difficulty in breathing, heart failure, and paralysis. It might sometimes lead to death despite treatment, especially in unvaccinated children. Centers for Disease Control and Prevention (CDC) recommends vaccines for infants, toddlers, teens, and adults to prevent diphtheria and its serious complications.

What Causes Diphtheria?

The bacteria usually multiply on the surface of the mucous membranes of the mouth, nose, or throat and cause inflammation of the tissues. The infection usually spreads through airborne droplets (when an infected person sneezes or coughs, a mist of contaminated droplets is released, which may be inhaled by the people nearby, and infect them). Handling an infected person’scontaminated belongings (such as tissues, towels,etc) can also transfer diphtheria causing bacteria to uninfected individuals.

Who Is More Prone to Diphtheria?

People who are at increased risk of catching diphtheria include:

• Children and adults who are not vaccinated.

• People who live in unhygienic or crowded conditions.

• People who travel to underdeveloped tropical countries where the prevalence of diphtheria is common.

What Are the Symptoms of Diphtheria?

The patients usually develop the symptoms a few days (an average of five days) after exposure to the bacteria. Symptoms of diphtheria include:

• Sore throat.

• Painful swallowing.

• Hoarseness.

• A general feeling of illness (malaise).

• Fever ranging between 100.4 to 102° F or 38 to 38.9° C.

• Children may also have an increased heart rate, chills, nausea, vomiting, and a headache.

• Swelling of the lymph nodes in the neck (called bull neck).

• The formation of a tough, gray layer of pseudomembrane near the tonsils and the throat by the bacteria, dead white blood cells, and other substances causes the narrowing of the airway and possible paralysis of the roof of the mouth. This causes difficulty in breathing among infected patients.

• An effect on the nerves, especially those supplying the muscles of the face, throat, arms, and legs, is produced by the toxin causing symptoms such as difficulty swallowing or moving the eyes, arms, or legs.

Some people with the infection show no apparent signs and are known to carry the bacteria in a carrier state by exhibiting only a mild illness. They are often unaware of the disease and are called carriers because they tend to spread the infection to others unknowingly.

A milder version of diphtheria affects only the skin and is more common in adults, leading to pain, erythema, inflammation, and sores or ulcers that are similar to other infections of the skin. A gray membrane covers these ulcers, and a few people have open sores that do not heal. It tends to spread by coming into contact with contaminated skin sores. This form is more common among people living in countries with poor hygiene habits.

What Are the Complications Associated With Diphtheria?

If the patient is unvaccinated or if the patient is not treated timely, it may lead to the following complications.

• Respiratory Problems: The toxin produced by diphtheria damages the tissues adjacent to the infection — usually in the nose and throat area and leads to the formation of a pseudomembrane. The pseudomembrane may cause people to make an unusual sound while inhaling and sometimes may extend into the airway, become detached and block the airway completely. The diaphragm (an important muscle used for inhaling) may become paralyzed due to the effect of the toxin on the associated nerves, sometimes leading to respiratory failure.

• Heart Damage: Other tissues of the body are damaged as the diphtheria toxin may spread through the bloodstream. When it damages the muscles of the heart, it causes complications such as inflammation of the heart muscle (myocarditis). The extent of damage from myocarditis can range from mild to severe. The effect of the toxin of the nerves related to the heart results in rapid heart rate, an abnormal heart rhythm, and low blood pressure. The impact on the muscles and nerves of the heart together may lead to abnormal heart rhythms, heart failure, and death.

• Nerve Damage: The toxins affect the nerves adversely. Typically they target the nerves that supply the throat and may cause difficulty swallowing. Inflammation of the nerves that supply the arms and legs also may cause muscle weakness.

• In case of severe infection, the toxins can also damage the kidneys.

With treatment, the majority of the patients survive these complications, but recovery is often slow. The fatality rate of diphtheria is about 5% to 10% of the time, primarily affecting children under age five or adults older than age 40.

Is There a Vaccine for Diphtheria?

Yes, with the advent of vaccines, diphtheria is not only treatable but also preventable.

The vaccine for diphtheria is usually combined with vaccines for tetanus and pertussis and is known as diphtheria, tetanus, and pertussis vaccine. The recent version of this vaccine is the DTaP(diphtheria, tetanus, and acellular pertussis) vaccine for children and the Tdap (combined tetanus, diphtheria, and acellular pertussis) vaccine for adolescents and adults. The vaccine is typically administered in the arm or thigh and is given as a series of five shots at the following ages:

• Two months.

• Four months.

• Six months.

• Fifteen to eighteen months.

• Four to six years.

Children are advised to receive their first booster shot at around 11 or 12 years of age following these shots. The subsequent booster shots are recommended at a ten-year interval to maintain the immunity (especially when traveling to a diphtheria-prone area).

What Are the Side Effects and Complications of the Vaccine?

The common side effects experienced by children include a mild fever, irritability, drowsiness, or pain at the injection site. In rare cases, the vaccine causes an allergic reaction (hives or a rash develops within minutes of the injection) which is treatable but severe in children.

What Are the Treatment Options for Diphtheria?

• Administering diphtheria antitoxin.

• Antibiotics.

• In case of respiratory symptoms, patients are usually hospitalized in intensive care units and are administered intravenous antibodies (antitoxin) to neutralize the diphtheria toxin. They are also given antibiotics, such as Penicillin or Erythromycin, for 14 days to kill the bacteria.

• Even after completing the antibiotic course, patients are advised to isolate (to prevent other people from being exposed) until two cultures are taken to confirm that the bacteria have been killed.

• For diphtheria of the skin, the sores are thoroughly cleaned with soap and water, and patients are given antibiotics for ten days.

• The infection does not guarantee immunity. Hence patients are advised to get vaccinated even after recovery to prevent infection.

• Recovery for patients with severe forms of infection is relatively slow. They are advised not to resume any physically exerting activity soon.

Conclusion:

Diphtheria can be managed easily if the symptoms are noted early and appropriate treatment measures are provided. The best way to prevent diphtheria is by getting the vaccine at the right age intervals. Diphtheria prognosis ranges from good to poor depending on how early in the infection the patient is treated and how well the patient responds to treatment. If the patient develops sepsis or bacteremia, or if the heart is involved, the prognosis is usually bleak.