Written by Joshua Belfer
Spoon Feed
Maintaining a high suspicion for botulism is crucial in making a prompt diagnosis and in reducing morbidity and mortality. This review highlights pearls and pitfalls of diagnosis and management.
A toxin like no other
A neuromuscular disorder characterized by descending paralysis, botulism occurs primarily in children and is caused by the botulinum neurotoxin, one of the most potent toxins known. While food-borne exposure (including honey in infants) can cause the disease, exposure to spores can be seen in soil exposure, contamination of wounds, or injection drug use. Spores germinate in the GI tract producing the neurotoxin, which then prevents the release of acetylcholine from neurons. The neurotoxin does not cross the blood brain barrier.
Presentation: Botulism classically presents with cranial nerve palsies and bilateral, descending symmetric flaccid paralysis. Typically occurring within 12-72 hours of the exposure, symptoms can be more subtle in infants, starting with constipation followed by bulbar symptoms, including weak cry or poor suck. Severe botulism cases may require respiratory support due to paralysis of the diaphragm.
Workup: Confirmatory testing can take 24-48 hours or more, and is done by identifying the presence of the toxin in the serum, gastric secretions, stool, or wound. A clinical diagnosis should guide treatment decisions while awaiting confirmatory testing.
Management: Botulism antitoxin is the treatment for botulism and should be initiated as soon as the diagnosis is highly suspected. Botulism has a 40-50% mortality rate if untreated. As the antitoxin cannot act on already-bound toxin, the sooner it is administered, the more free toxin can be inactivated. Infants should receive Baby Botulism Immunoglobulin (BabyBIG), which is only available through the California Department of Health Services. Respiratory care is the most important aspect of management. Antibiotics have not been found to be successful and can lead to worsening of symptoms.
Pearls and Pitfalls:
- Symptoms can be differentiated from anticholinergic toxicity by the lack of flushed skin, hallucinations, tachycardia, and altered mental status.
- Symptoms in infants can be subtle but may include mydriasis, weak cry, hypotonia, constipation, and third cranial nerve palsy.
- Diseases of the neuromuscular junction, such as myasthenia gravis and Guillain-Barré Syndrome, can also present with weakness and mimic botulism.
How will this change my practice?
Botulism is uncommon, but early diagnosis can significantly impact morbidity and mortality. Families are usually well educated about avoiding honey in young infants, environmental exposures such as in family members who work in construction may be more difficult to stay away from. Relying on your team – especially nurses – can help raise your suspicion for botulism; for example, I have had nurses approach me to tell me the baby’s cry seems weak, or that they watched the baby feed and they seemed to have a poor suck. Paying close attention to subtle symptoms – with the help of your team – can allow you to initiate treatment early in the course of this potentially lethal disease.
Source
High risk and low prevalence diseases: Botulism. Am J Emerg Med. 2024 Aug;82:174-182. doi: 10.1016/j.ajem.2024.06.018. Epub 2024 Jun 20. PMID: 38925095.
