What Is Lockjaw? Symptoms & Treatment

Lockjaw, or tetanus, is a rare but serious and life-threatening disease that is caused by a bacterial infection that first causes stiffness in the jaw and neck.

What is lockjaw (tetanus)?

Lockjaw is another term for tetanus — a severe bacterial disease that occurs when a particular bacterium (Clostridium tetani) enters the human body and produces dangerous exotoxins. This condition affects nerves and muscles. 

It’s called lockjaw because the bacterial infection causes stiffness in the neck and jaw area, causing them to lock up. This stiffness can then spread to other parts of the body.

What are the symptoms of lockjaw (tetanus)?

The first and most common symptom of lockjaw is a feeling of stiffness in the jaw and/or neck. For someone who has not been vaccinated against tetanus and has possibly been in contact with bacteria in the environment (such as working in dirt or manure), this locked-jaw feeling should serve as a warning sign that they may be suffering from lockjaw and should seek immediate medical attention. 

Other symptoms of lockjaw include the following:

• Muscle spasms

• Breathing and swallowing problems 

• Drooling

• Fever

• Sweating

• High blood pressure

• Painful swelling throughout the body

• Seizures

• Accelerated heart rate

• Loss of control of bowel movements and urine

• Abdominal tightness

Anyone who suspects they may have lockjaw should seek immediate medical care. Lockjaw is an extremely dangerous condition and can result in death related to heart or breathing problems.

What causes the muscle & nerve pain of lockjaw (tetanus)?

The bacteria that cause lockjaw is found in the environment, particularly in manure, soil, and dust. Once the spores of this bacteria enter the body through breaks in the skin, they spread through the blood and lymph system as active bacteria and produce two exotoxins, tetanolysin and tetanospasmin.  

Tetanospasmin, also called tetanus toxin, is a neurotoxin (a poison that affects the nervous system) and one of the strongest toxins known. It affects the central nervous system, peripheral motor skills, the brain, the spinal cord, and the sympathetic nervous system. 

One of the actions of tetanus toxin is blocking communication between the spinal cord and muscles. It does this by interfering with neurotransmitters, thus blocking nerve signals coming from the spinal cord. This is what causes the muscle spasms that people with lockjaw experience. 

The muscle spasms can become progressively more severe. They can become strong enough to tear muscles, cause trauma, and trigger spinal fractures. Seizures may also occur as the central nervous system is affected.

How common is lockjaw?

Because of widespread tetanus vaccinations, lockjaw is very rare.

Tetanus vaccine

In 1889, Kitasato Shibasaburo presented research identifying the tetanus toxin and the possibility of antibodies that could neutralize it. By 1897, Edmond Nocard had developed an antitoxin that was used in World War I. 

In the 1920s a new method of inactivating the tetanus toxin was created with formaldehyde. In 1924, the tetanus toxoid was developed. 

A toxoid is a modified toxin that is no longer toxic but can trigger the correct immune response and thus be used as a vaccine. The tetanus toxoid was widely used during World War II. 

Vaccines containing the tetanus toxoid became part of the childhood vaccine routine in the 1940s. Today, the vaccine containing the tetanus toxoid is usually combined with other toxoids, including the diphtheria toxoid. In 2019, the percentage of adolescents covered by a tetanus toxoid-containing vaccine was over 90 percent. The percentage of adults covered was lower, at about 63 percent. 

Antitoxin levels do decrease over time, and 10 years after a last dose, the protection may be only minimal. Booster vaccine shots are recommended every 10 years and for those who have sustained a more major cut or wound and haven’t had a tetanus vaccine in over five years.

Lockjaw (tetanus) statistics

• When tetanus vaccines were first introduced into childhood treatment routines in the 1940s, approximately 500 to 600 cases of lockjaw were reported each year. 

• Since the mid-1970s, that number had dropped to around 50 to 100 cases annually. 

• In 2018, there were 23 cases of lockjaw (tetanus) reported with no deaths.

How is tetanus spread?

Lockjaw infection is usually caused by a deep cut or wound being infected by the Clostridium tetani bacterium on an unvaccinated person. The bacteria may enter through a puncture wound or an unexpected accident, like stepping on an old nail or getting a dirty splinter caught in the skin. 

Other incidents that may result in lockjaw infection include the following:

• Burns

• Exposed broken bone or fractures

• Insect or animal bites

• Dental infection

• Intravenous drug use 

• Surgical procedures

• Injuries that leave skin openings vulnerable

Because more serious wounds are more likely to be cared for with caution or in a hospital setting, a high percentage of lockjaw cases were caused by minor wounds in recent times.

More about the spread of lockjaw (tetanus)

• Lockjaw can occur anywhere, but it is more likely to be a problem in areas with a dense population and in hot, damp climates with high-organic matter soil.

• Lockjaw is not spread person to person.

• In places with temperate climates, lockjaw is more common in the summer. In tropical locales, it is common year-round, but it may be at its peak during the wet season.

• Because the tetanus toxin is so strong, having tetanus does not protect you from future occurrences of tetanus. 

• The diagnosis of tetanus is clinical and does not involve confirmation from bacteria or lab testing.

What are the different types of tetanus?

Generalized tetanus is the most common type of lockjaw, accounting for more than 80 percent of reported cases. 

Generalized tetanus is characterized by a “descending” pattern of the disease. It starts with a lockjaw feeling. Then, it progresses to stiffness in the neck, trouble swallowing, and abdominal tightness. Fever, sweating, spasms, high blood pressure, episodes of rapid heart beating, and serious and continuous spasms are also characteristics of this form of tetanus.

These are the other types of lockjaw:

• Localized tetanus occurs when an individual has an injury and experiences muscle spasms only in the area they were injured. The illness is usually milder, but it may be a precursor to the beginning of generalized tetanus illness. This type of lockjaw is uncommon.

• Cephalic tetanus is rare and can occur with otitis media (middle ear infection). This type of lockjaw involves cranial nerves and can also occur after a head injury. 

• Neonatal tetanus is generalized tetanus that occurs in infants (newborns). In most cases, the infant is born without passive immunity because the mother is unvaccinated or unprotected. The infection may occur when an umbilical cord is cut unhygienically, heals improperly, or was touched with an unsterilized object.

What is the treatment for lockjaw?

Anyone infected with lockjaw should go to the emergency room as quickly as possible, and contact their local health department. 

The first step in treatment will be a thorough cleaning of the wound or injury. Airway support will also be provided if spasms are impacting breathing. 

For short-term protection, a hospital or doctor may administer tetanus immune globulin (TIG) or immune globulin intravenous (IGIV). These help to remove tetanus toxins that have not yet bonded in the system. Antibiotics or anti-spasm medication may also be given. 

As soon as the condition is stabilized, a vaccine for long-term immunity will be advised.

What are the possible complications of tetanus?

Even treated, lockjaw can cause death. Approximately 1 to 2 cases out of 10 will result in a fatality. 

Other serious complications of lockjaw include the following:

• Broken bones

• Pneumonia

• Pulmonary embolism (blood clot in the lung)

• Vocal cord spasms

• Heart and breathing problems

• Seizures

Who is at risk for lockjaw (tetanus)?

People who are unvaccinated are the most vulnerable to lockjaw infection. People over 60 and those who have not received a tetanus vaccination in over 10 years are also at higher risk.

Other individuals who may be more susceptible to lockjaw infection include the following: 

• Intravenous drug users

• Those with a compromised immune system

• People with diabetes

• Humanitarian aid workers based outside of the U.S. on projects that involve the outside environment, such as building houses or farming