BOTULISM

Botulism is an acute neurologic disorder that causes potentially life-threatening neuroparalysis due to a neurotoxin produced by Clostridium botulinum. The 3 main clinical presentations of botulism are as follows:

• Infant botulism
• Foodborne botulism
• Wound botulism

Essential update: FDA approves first heptavalent botulism antitoxin

On March 22, 2013, the FDA approved the first botulism antitoxin that can neutralize all 7 known botulinum nerve toxin serotypes. The heptavalent antitoxin is derived from horse plasma and is the only drug available for treating botulism patients over 1 year of age, including adults. It is also the only available drug for treating infant botulism that is not caused by nerve toxin type A or B.^{[1, 2, 3, 4]}

Signs and symptoms

More than 90% of patients with botulism have 3-5 of the following signs or symptoms:

• Nausea
• Vomiting
• Dysphagia
• Diplopia
• Dilated/fixed pupils
• Extremely dry mouth unrelieved by drinking fluids

Generally, botulism progresses as follows:

• Preceding or following the onset of paralysis are nonspecific findings such as nausea, vomiting, abdominal pain, malaise, dizziness, dry mouth, dry throat, and, occasionally, sore throat
• Cranial nerve paralysis manifests as blurred vision, diplopia, ptosis, extraocular muscle weakness or paresis, fixed/dilated pupils, dysarthria, dysphagia, and/or suppressed gag reflex
• Additional neurologic manifestations include symmetrical descending paralysis or weakness of motor and autonomic nerves
• Respiratory muscle weakness may be subtle or progressive, advancing rapidly to respiratory failure

The autonomic nervous system is also involved in botulism, with manifestations that include the following:

• Paralytic ileus advancing to severe constipation
• Gastric dilatation
• Bladder distention advancing to urinary retention
• Orthostatic hypotension
• Reduced salivation
• Reduced lacrimation

Other neurologic findings include the following:

• Changes in deep tendon reflexes, which may be either intact or diminished
• Incoordination due to muscle weakness
• Absence of pathologic reflexes and normal findings on sensory and gait examinations
• Normal results on mental status examination