Trismus
Commonly known as “lockjaw,” trismus is a prolonged and painful tonic spasm of the masticatory jaw muscles. This characteristic early sign of tetanus is produced by the neuromuscular effects of tetanospasmin, a potentially lethal exotoxin. It can also result from drug therapy; occasionally, a milder form may accompany neuromuscular involvement in other disorders, or infection or disease of the jaw, teeth, parotid glands, or tonsils.
History and physical examination
Ask the patient if he experienced a recent injury (even a slight wound), infection, or animal bite. Does he have a history of epilepsy, neuromuscular disease, or endocrine or metabolic disorders? Obtain a complete drug history, including self-injected drugs because the use of a contaminated needle may produce tetanus. Also, ask about paresthesia or pain in the throat, jaw, neck, or shoulders.
Examination of the oral cavity may be difficult or impossible to perform. If possible, examine the pharynx, tonsils, oral mucosa, gingivae, and teeth. Perform a neurologic assessment, evaluating cranial nerve, motor, and sensory function and deep tendon reflexes. Also, check the jaw jerk reflex. An extremely hyperactive response and a careful patient history usually establish the diagnosis. (See Performing the jaw jerk test, page 772.)
Medical causes
Hypocalcemia
Severe hypocalcemia can produce trismus and cramping spasms in virtually all muscle groups, except those of the eye. It also causes fatigue, weakness, chorea, and palpitations. Chvostek’s and Trousseau’s signs may be elicited.
Peritonsillar abscess
This disorder occurs after an episode of acute tonsillitis when infection penetrates the tonsillar capsule and surrounding deeper tissues. Symptoms include severe sore throat, trismus, odynophagia, deviation of the uvula, and fever.
Rabies
Trismus commonly develops after a prodromal period of fever, headache, photophobia, hyperesthesia, and increasing restlessness and agitation. Other neuromuscular effects include excessive salivation, painful laryngeal and pharyngeal muscle spasms and, possibly, respiratory distress.
Seizure Disorders
Trismus commonly occurs during a generalized tonic-clonic seizure along with spasms of other facial muscles, the limbs, and the trunk.
Temporomandibular joint syndrome
This syndrome causes trismus, mandibular dysfunction, and facial pain. The pain may range from a severe dull ache to an intense spasm that radiates to the cheek, temple, lower jaw, ear, mastoid area, neck, or shoulders. Earache occurs without involvement of the tympanic membrane or external auditory canal.
Tetanus
This acute, life-threatening infection is heralded by trismus, which typically appears within 14 days of the initial infection. The painful spasms increase in frequency and intensity during the initial disease stage, then gradually subside. Although trismus is commonly the first sign of tetanus, it occasionally follows a short prodromal period of headache, restlessness, irritability, slight fever, chills, swelling at the wound site, and dysphagia. As the disease progresses, painful involuntary muscle spasms spread to other areas, such as the abdomen, producing boardlike rigidity; the back, resulting in opisthotonos; the face, producing a characteristic grotesque grin (risus sardonicus); or possibly the laryngeal or chest wall muscles. Tachycardia, diaphoresis, hyperactive deep tendon reflexes, and seizures may also develop.
Other causes
Drugs
Phenothiazines (particularly the piperazine derivatives such as fluphenazine) and other antipsychotics may produce an acute dystonic reaction marked by trismus, involuntary facial movements, and tonic spasms in the limbs. These complications usually occur early in drug therapy, sometimes after the initial dose.
Strychnine poisoning
In this potentially fatal condition, tonic seizures characterized by trismus, leg muscle rigidity, and respiratory muscle spasm follow early symptoms of irritability and twitching.
Special considerations
Maintain a quiet environment for the patient with trismus; darken his room and keep all stimulation to a minimum. Administer a sedative as needed.
Because inadequate ventilation from laryngeal or respiratory muscle spasm is a constant threat during the acute phase of tetanus, constantly assess the patient’s respiratory status and make sure that oxygen and emergency airway equipment are readily available. To treat tetanus, expect to administer human tetanus immune globulin, which neutralizes unbound toxin.
Administer I.V. fluids to prevent dehydration if the patient can’t drink fluids. If trismus is prolonged enough to affect his nutritional status, the patient may require parenteral nutrition. If the patient can’t speak, make sure that he has a pen and paper and that his call bell is within reach at all times.
Pediatric pointers
Trismus in a neonate can result from tetanus neonatorum, which occurs when the tetanus toxin is introduced through the umbilical cord. Trismus usually develops within 10 days of birth.
Patient counseling
Teach the patient with tetanus about the importance of annual booster injections to ensure immunization.
Pictures
Book Source Details
- Book Title: Professional Guide to Signs & Symptoms (Fifth Edition)
- Author(s): Springhouse
- Year of Publication: 2006
- Copyright Details: Professional Guide to Signs & Symptoms (Fifth Edition), Copyright © 2006 Lippincott Williams & Wilkins.
Other Book Chapters Related to Trismus
Read excerpts from these other book chapters related to Trismus:
Medical Books Excerpts
- JAW PAIN
- "Algorithmic Diagnosis of Symptoms and Signs" (2003)
- [ read ]
- TRISMUS
- "Algorithmic Diagnosis of Symptoms and Signs" (2003)
- [ read ]
- Jaw pain
- "Handbook of Signs & Symptoms (Third Edition)" (2006)
- [ read ]
- Jaw pain
- "Professional Guide to Signs & Symptoms (Fifth Edition)" (2006)
- [ read ]
- Trismus
- "Professional Guide to Signs & Symptoms (Fifth Edition)" (2006)
- [ read ]
- Jaw pain
- "Alarming Signs and Symptoms: Lippincott Manual of Nursing Practice Series" (2007)
- [ read ]
- Muscle spasms
- "Alarming Signs and Symptoms: Lippincott Manual of Nursing Practice Series" (2007)
- [ read ]
- Jaw pain
- "Signs & Symptoms: A 2-in-1 Reference for Nurses" (2007)
- [ read ]
- Jaw pain
- "Nursing: Interpreting Signs and Symptoms" (2007)
- [ read ]
Copyright Details: Professional Guide to Signs & Symptoms (Fifth Edition), Copyright © 2008 Williams & Wilkins.
More About Causes of Trismus
» Next page: Muscle spasms [Muscle cramps] (Professional Guide to Signs & Symptoms (Fifth Edition))
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