10 Warning Signs and Symptoms of Diphtheria You Should Know

Diphtheria is a serious bacterial infection caused by Corynebacterium diphtheriae that primarily affects the nose, throat, and sometimes the skin. Despite being preventable through vaccination, diphtheria remains a concern in areas with low immunization rates. Understanding the symptoms of diphtheria is crucial for early detection and prompt medical intervention, as this disease can lead to severe complications if left untreated.

The infection produces a toxin that can damage the heart, kidneys, and nervous system, making it potentially life-threatening. Recognizing the warning signs early can make a significant difference in treatment outcomes. Here are the most important symptoms of diphtheria that everyone should be aware of.

1. Thick Gray or White Membrane in the Throat

One of the most characteristic and recognizable symptoms of diphtheria is the formation of a thick, gray or white membrane that covers the tonsils and throat. This pseudomembrane is composed of dead cells, bacteria, and other substances produced by the infection.

The membrane typically:

• Appears dirty gray or white in color
• Adheres tightly to the underlying tissue
• May bleed if you attempt to remove it
• Can extend from the tonsils to cover the pharynx and larynx
• May obstruct breathing if it becomes large enough

This membrane distinguishes diphtheria from other throat infections like strep throat or common viral infections, making it a critical diagnostic sign that requires immediate medical attention.

2. Sore Throat

A sore throat is often one of the earliest symptoms of diphtheria, appearing within 2-5 days after infection. While sore throats are common with many illnesses, the sore throat associated with diphtheria has some distinctive characteristics.

The throat pain in diphtheria:

• May start as mild discomfort and progressively worsen
• Can make swallowing difficult and painful
• Is often accompanied by a feeling of tightness in the throat
• May be less severe than expected given the visible throat changes

It’s important to note that not all cases of diphtheria present with severe throat pain, which is why other symptoms should also be carefully monitored.

3. Fever

Fever is a common symptom of diphtheria, though it is typically low-grade, usually not exceeding 101°F (38.3°C). This relatively mild fever can be misleading, as it may cause people to underestimate the seriousness of the infection.

The fever associated with diphtheria:

• Usually ranges from 100°F to 101°F (37.8°C to 38.3°C)
• May be accompanied by chills
• Tends to persist throughout the acute phase of illness
• Can be accompanied by general malaise and fatigue

The presence of even a low-grade fever combined with other respiratory symptoms should prompt medical evaluation, especially in unvaccinated individuals or those in areas where diphtheria is present.

4. Swollen Lymph Nodes in the Neck

Significant swelling of the lymph nodes in the neck, known as cervical lymphadenopathy, is a prominent feature of diphtheria. In severe cases, this swelling can be so pronounced that it creates a characteristic appearance called “bull neck.”

The lymph node swelling in diphtheria:

• Affects lymph nodes on both sides of the neck
• Can cause visible swelling that changes the neck’s contour
• May be tender to the touch
• Often accompanied by swelling of surrounding soft tissues
• Creates the distinctive “bull neck” appearance in severe cases

This symptom indicates that the body’s immune system is responding to the infection and is often associated with more severe cases of diphtheria.

5. Difficulty Breathing or Rapid Breathing

Respiratory difficulties are among the most dangerous symptoms of diphtheria and require immediate medical attention. The thick membrane in the throat can partially or completely obstruct the airway, leading to breathing problems.

Breathing difficulties may manifest as:

• Shortness of breath or labored breathing
• Rapid breathing rate (tachypnea)
• Noisy breathing or stridor (a high-pitched sound when breathing in)
• Flaring of the nostrils when breathing
• Chest retractions (skin pulling in between ribs during breathing)
• Cyanosis (bluish discoloration of lips or skin due to lack of oxygen)

These symptoms indicate severe airway compromise and constitute a medical emergency requiring immediate intervention to maintain adequate oxygen levels.

6. Hoarseness or Changes in Voice

When diphtheria affects the larynx (voice box), it can cause significant changes in voice quality. This symptom, known as laryngeal diphtheria, occurs when the membrane extends beyond the pharynx to involve the larynx.

Voice changes in diphtheria include:

• Hoarseness or a raspy quality to the voice
• Weakened voice that sounds strained
• Complete loss of voice (aphonia) in severe cases
• A muffled quality when speaking
• Difficulty projecting the voice

Hoarseness combined with other diphtheria symptoms should raise immediate concern, as it suggests the infection is affecting the lower respiratory structures.

7. Difficulty Swallowing

Difficulty swallowing, medically termed dysphagia, is a common and distressing symptom of diphtheria. This occurs due to the combination of throat inflammation, the presence of the membrane, and swelling of surrounding tissues.

Swallowing difficulties in diphtheria may present as:

• Pain when swallowing (odynophagia)
• Sensation of food getting stuck in the throat
• Inability to swallow solid foods
• Drooling due to inability to swallow saliva
• Choking sensation when attempting to swallow
• Regurgitation of food or liquids through the nose

Severe swallowing difficulties can lead to dehydration and nutritional problems, particularly in children, and may require medical support for adequate hydration and nutrition.

8. Weakness and Fatigue

General weakness and overwhelming fatigue are common systemic symptoms of diphtheria. These symptoms result from the body’s immune response to the infection and the effects of the diphtheria toxin on various body systems.

The weakness and fatigue associated with diphtheria:

• Can be profound and debilitating
• Often appears early in the course of the disease
• May persist for weeks even after the acute infection resolves
• Can affect daily activities and normal functioning
• May be accompanied by muscle weakness

In severe cases, the diphtheria toxin can affect the nervous system, leading to more specific neurological weakness that may develop weeks after the initial infection.

9. Nasal Discharge

When diphtheria affects the nasal passages, it causes a characteristic nasal discharge. Nasal diphtheria is more common in infants and young children and may be the only manifestation of the disease in some cases.

The nasal discharge in diphtheria typically:

• Starts as a clear, watery discharge
• Becomes blood-tinged or serosanguineous (blood-stained)
• May be foul-smelling
• Can cause crusting around the nostrils
• Usually affects one nostril initially, then may spread to both
• May be accompanied by a membrane visible in the nose

Nasal diphtheria is often milder than pharyngeal diphtheria but can still spread the infection to others and should not be ignored.

10. Skin Lesions (Cutaneous Diphtheria)

While diphtheria primarily affects the respiratory tract, it can also manifest as skin infections, particularly in tropical climates or among homeless populations with poor hygiene. Cutaneous diphtheria presents differently from respiratory diphtheria.

Skin manifestations of diphtheria include:

• Painful, punched-out ulcers with well-defined edges
• Gray membrane covering the ulcer base
• Surrounding area may be red and swollen
• Lesions that are slow to heal
• Can occur anywhere on the body but commonly on the legs and feet
• May start as a blister or pustule before becoming an ulcer

Cutaneous diphtheria is generally less severe than respiratory diphtheria but can still produce toxin and cause systemic complications. It also serves as an important reservoir for transmitting the bacteria to others.

Main Causes of Diphtheria

Understanding the causes of diphtheria helps in prevention and early recognition of risk factors. The disease is caused by specific bacteria and spreads through particular routes.

Bacterial Infection

Diphtheria is caused by the bacterium Corynebacterium diphtheriae. Some strains of this bacterium produce a powerful toxin that causes most of the serious symptoms and complications of the disease. The bacteria typically infect the mucous membranes of the respiratory tract.

Person-to-Person Transmission

The disease spreads primarily through respiratory droplets when an infected person coughs or sneezes. It can also spread through:

• Direct contact with respiratory secretions
• Contaminated personal items (towels, toys, drinking glasses)
• Contact with skin lesions in cutaneous diphtheria
• Asymptomatic carriers who harbor the bacteria without showing symptoms

Lack of Vaccination

The primary risk factor for developing diphtheria is inadequate vaccination. The diphtheria vaccine is highly effective, and most cases occur in:

• Unvaccinated individuals
• People who have not completed the full vaccination series
• Adults who have not received booster doses
• Populations in areas with low vaccination coverage

Environmental and Social Factors

Certain conditions increase the risk of diphtheria transmission:

• Crowded living conditions
• Poor sanitation and hygiene
• Lack of access to healthcare
• Travel to or residence in endemic areas
• Compromised immune system

Prevention of Diphtheria

Diphtheria is a vaccine-preventable disease, and prevention strategies are highly effective when properly implemented.

Vaccination

The most effective way to prevent diphtheria is through vaccination:

• Childhood vaccination: Children should receive the DTaP vaccine (diphtheria, tetanus, and pertussis) at 2, 4, 6, and 15-18 months of age, with a booster at 4-6 years
• Adolescent and adult boosters: A Tdap booster should be given at age 11-12, followed by Td boosters every 10 years throughout adulthood
• Catch-up vaccination: Unvaccinated or incompletely vaccinated individuals should complete the vaccination series regardless of age
• Travel vaccination: Ensure vaccination is up-to-date before traveling to areas where diphtheria is endemic

Good Hygiene Practices

Practicing good hygiene can reduce the risk of transmission:

• Frequent handwashing with soap and water
• Covering mouth and nose when coughing or sneezing
• Avoiding sharing personal items like utensils, cups, or towels
• Proper wound care to prevent cutaneous diphtheria

Isolation and Quarantine

When cases occur, public health measures are essential:

• Isolating infected individuals until they are no longer contagious
• Identifying and monitoring close contacts
• Providing prophylactic treatment to close contacts as recommended by healthcare providers
• Testing contacts to identify carriers

Public Health Surveillance

Maintaining strong public health systems helps prevent outbreaks:

• Disease surveillance and reporting
• Maintaining high vaccination coverage in the population
• Rapid response to cases and outbreaks
• Public education about the importance of vaccination

Frequently Asked Questions About Diphtheria

How quickly do diphtheria symptoms appear after exposure?

The incubation period for diphtheria is typically 2 to 5 days after exposure to the bacteria, though it can range from 1 to 10 days. Symptoms usually begin gradually with a sore throat and low-grade fever before progressing to more characteristic signs like the gray membrane.

Can you get diphtheria more than once?

Yes, it is possible to get diphtheria more than once. Having diphtheria does not provide complete lifelong immunity. Vaccination remains the most reliable protection, and completing the full vaccine series plus regular boosters is essential even if you’ve had the disease.

Is diphtheria contagious before symptoms appear?

Yes, people infected with diphtheria can spread the disease to others before symptoms develop. Additionally, some people can be asymptomatic carriers who harbor the bacteria without showing symptoms but can still transmit it to others. This is why vaccination of the entire community is important.

How is diphtheria different from strep throat?

While both can cause sore throat, diphtheria produces a characteristic thick gray or white membrane that adheres tightly to the throat and bleeds if removal is attempted. Diphtheria also typically causes a milder fever and more prominent neck swelling than strep throat. The membrane is the key distinguishing feature that requires immediate medical attention.

Can adults get diphtheria even if they were vaccinated as children?

Yes, adults can develop diphtheria if immunity from childhood vaccination has waned. Immunity from the diphtheria vaccine decreases over time, which is why booster shots (Td or Tdap) are recommended every 10 years throughout adulthood. Adults who have not kept up with booster vaccinations are at increased risk.

What should I do if I think I or someone I know has diphtheria?

Seek immediate medical attention if you suspect diphtheria. Call ahead to inform the healthcare facility so they can take appropriate precautions. Do not wait for symptoms to worsen. Diphtheria is a medical emergency that requires prompt diagnosis and treatment. If you’ve been in close contact with someone diagnosed with diphtheria, contact your healthcare provider even if you don’t have symptoms.

Are certain people more at risk for severe diphtheria?

Yes, unvaccinated children under 5 years old and adults over 60 are at higher risk for severe disease. People with weakened immune systems, those living in crowded conditions with poor sanitation, and individuals in areas with low vaccination rates are also at increased risk. Additionally, people who haven’t received their routine booster vaccinations are more susceptible.

Can diphtheria be prevented through natural immunity?

No, relying on natural immunity is not recommended for diphtheria prevention. The disease is too dangerous to risk natural infection, which can cause severe complications including heart damage, nerve damage, and death. Vaccination is the safe and effective way to develop immunity without risking the serious consequences of the disease itself.

References:

• Centers for Disease Control and Prevention (CDC) – Diphtheria
• World Health Organization (WHO) – Diphtheria Fact Sheet
• Mayo Clinic – Diphtheria
• National Health Service (NHS) – Diphtheria
• MedlinePlus – Diphtheria