A 38-year-old homeless man is brought to the emergency department due to severe muscle pain and stiffness. He arrived at a homeless shelter 2 days ago, and the manager says that he has been restless and irritable. The patient has a history of alcohol abuse and injection drug use. Temperature is 37.7 C (100 F), blood pressure is 150/90 mm Hg, and pulse is 102/min. Both pupils are normal, equal, and reactive to light. There are marks on the patient's arms from previous injections as well as several abrasions and lacerations on the lower extremities. He is unable to open his mouth completely. Painful spasms of the neck muscles are triggered by physical stimuli. Which of the following is the most likely cause of this patient's current condition?

Question

A 38-year-old homeless man is brought to the emergency department due to severe muscle pain and stiffness.  He arrived at a homeless shelter 2 days ago, and the manager says that he has been restless and irritable.  The patient has a history of alcohol abuse and injection drug use.  Temperature is 37.7 C (100 F), blood pressure is 150/90 mm Hg, and pulse is 102/min.  Both pupils are normal, equal, and reactive to light.  There are marks on the patient's arms from previous injections as well as several abrasions and lacerations on the lower extremities.  He is unable to open his mouth completely.  Painful spasms of the neck muscles are triggered by physical stimuli.  Which of the following is the most likely cause of this patient's current condition?

Quizplus · Accepted Answer

11ec25c8_d48e_fbd4_bc81_994ed5495d40_MD0003_00 This patient with fever, muscle stiffness, trismus/lockjaw (inability to open his mouth completely), and painful muscle spasms triggered by physical stimuli likely has tetanus. This disorder occurs when Clostridium tetani, which is normally found in soil, enters the body through a break in the skin (eg, puncture wound, lower extremity abrasions/lacerations). This bacterium then secretes a toxin that binds to the peripheral nerve terminals and, using retrograde axonal transport, arrives at a central nervous system synapse, where it blocks the release of inhibitory neurotransmitters glycine and GABA across the synaptic cleft. Because of this mechanism, symptoms usually occur within a few days to several weeks following inoculation and can include sweating, dysphagia, labile blood pressure, and tachycardia. Tetanus occurs almost exclusively in those with poor access to health care as they are more likely to be unvaccinated or inadequately immunized. For those who become ill, the infected wound should be debrided, antibiotics should be started, and human tetanus immunoglobulin (to bind residual circulating toxin) and tetanus toxoid should be administered. (Choice A) Guillain-Barré syndrome is an acute immune-mediated, demyelinating polyneuropathy, usually postinfectious, that classically presents with ascending weakness, minor sensory symptoms (acral paresthesias), and areflexia. Painful muscle spasms and trismus are not typically seen. (Choice B) Botulism is caused by Clostridium botulinum toxin, leading to impairment of presynaptic acetylcholine release. It usually presents with symmetric descending flaccid paralysis, blurred vision, and areflexia and can include diaphragmatic paralysis. (Choice C) Meningitis is a central nervous system infection due to microbial invasion that can present as fever, confusion, and stiff neck, but is unlikely to cause painful muscle spasms. Similarly, rabies can cause fever, confusion, and spasms, although hydrophobia and aerophobia (thought to be due to pharyngeal spasms) are classic. Trismus would not usually be seen in either of these conditions. (Choice D) Opiate withdrawal can present with tachycardia, hypertension, diaphoresis, restlessness, and irritability. Trismus and muscle spasms are unlikely. (Choice E) Polymyositis is an inflammatory myopathy mediated by cytotoxic T-lymphocytes. It usually presents with gradual proximal muscle weakness without prominent pain, muscle spasms, or trismus. Educational objective: Tetanus is a presynaptic neuromuscular junction disorder caused by the Clostridium tetani toxin, which blocks the release of the inhibitory neurotransmitters glycine and GABA across the synaptic cleft, leading to fever, painful muscle spasms, and trismus (lockjaw). It is usually seen only in those who are unvaccinated or incompletely immunized. References: A forgotten diagnosis in emergency department: tetanus. (http://www.ncbi.nlm.nih.gov/pubmed/21863620) Trismus, the first symptom in a challenging diagnosis of tetanus. (http://www.ncbi.nlm.nih.gov/pubmed/26869628)

A 38-Year-Old Homeless Man Is Brought to the Emergency Department