From the Guidelines
Botulism symptoms include muscle weakness that starts in the face and moves downward, causing drooping eyelids, blurred vision, difficulty swallowing, slurred speech, and dry mouth, and can progress to life-threatening respiratory failure. According to the clinical guidelines for diagnosis and treatment of botulism, 2021, published in the MMWR Recommendations and Reports 1, botulism is a rare, neurotoxin-mediated, life-threatening disease characterized by flaccid descending paralysis. The symptoms of botulism can be similar regardless of the exposure route, which can occur through ingestion of toxin, bacterial colonization of a wound, or high-concentration cosmetic or therapeutic injections of toxin.
Some of the key symptoms of botulism include:
- Descending paralysis (93% of cases) 1
- Dysphagia (85% of cases) 1
- Weakness or fatigue (85% of cases) 1
- Ptosis (81% of cases) 1
- Blurred vision (80% of cases) 1
- Difficulty speaking (78% of cases) 1
- Shortness of breath (65% of cases) 1
- Dry mouth (63% of cases) 1
- Constipation (30% of cases) 1
In infants, symptoms may appear as lethargy, poor feeding, constipation, weak cry, and decreased movement. Foodborne botulism may initially cause nausea, vomiting, and abdominal cramps before neurological symptoms develop. These symptoms typically appear 12-36 hours after exposure to the botulinum toxin, which blocks nerve signals to muscles by preventing the release of acetylcholine. Botulism is a medical emergency requiring immediate treatment, typically with antitoxin administration, and can last weeks to months, often requiring intensive supportive care including mechanical ventilation until the body produces new nerve endings to replace those damaged by the toxin 1.
From the Research
Botulism Symptoms
The symptoms of botulism can be severe and potentially life-threatening. According to 2, the symptoms include:
- Progressive weakness
- Bulbar signs such as:
- Blurred vision
- Diplopia
- Mydriasis
- Dysphagia
- Dysarthria
- Respiratory failure with normal sensation and mentation
Clinical Syndrome
As described in 3, all forms of botulism produce a distinct clinical syndrome characterized by:
- Symmetrical cranial nerve palsies
- Descending, symmetric flaccid paralysis of voluntary muscles
- Potential progression to respiratory compromise and death
Treatment and Outcomes
Studies such as 4 have shown that treatment with botulinum antitoxin, such as Botulism Antitoxin Heptavalent (BAT), can be effective in managing botulism symptoms. Early treatment (within 2 days of symptom onset) is associated with:
- Shorter hospital stays
- Shorter intensive care unit (ICU) stays
- Shorter duration of mechanical ventilation
Reversal of Severe Sequelae
In some cases, patients may experience severe sequelae from botulinum toxin injection, such as dysphagia, dyspnea, or distant and autonomic symptoms. As reported in 5 and 6, pyridostigmine may be used to reverse these symptoms by preventing the breakdown of acetylcholine at the neuromuscular junction.