Botulinum is a potent neurotoxin that is derived primarily from Clostridium botulinum. Botulinum toxin blocks release of acetylcholine, which results in decreased activation of muscarinic and nicotinic receptors. Initial effects may include nonspecific findings such as nausea and vomiting, constipation, and throat complaints. The classic neurologic findings are due to the lack of receptor activation of the nicotinic receptor at the neuromuscular junction. Dysarthria, dysphagia, diplopia, and mydriasis progress to a descending symmetric paralysis.
The common types of botulism include foodborne (ingestion of preformed toxin), infantile (in vivo production of toxin), and wound botulism (in vivo production of toxin). While foodborne botulism has the features classically described, infantile botulism manifests as the constipated, floppy baby. Wound botulism is most commonly associated with “skin popping,” a technique of subcutaneous injection of an illicit drug, usually black tar heroin. Diagnosis is initially a clinical one, with subsequent verification via a murine assay of the presence of botulinum toxin in a patient sample. This assay is performed through either the state department of health or the Centers for Disease Control and Prevention.
Infantile Botulism. The floppy, constipated baby is a classic presentation of infantile botulism. (Photo contributor: Centers for Disease Control and Prevention.)
Management and Disposition
Any patient in whom botulism is suspected should be admitted to the hospital. Careful monitoring of the airway status is important to ensure that the patient has adequate ventilatory capacity. The local health department should be notified to assist with the procurement of botulinum antitoxin for foodborne and wound botulism patients. Human botulinum immune globulin is available through the California Department of Health for the treatment of infantile botulism.
The initial chief complaint of a patient with wound botulism may be “sore throat” since the patient has dry mucous membranes and difficulty swallowing.
Since botulinum toxin does not cross the blood-brain barrier, the mental status should not be affected unless the patient has respiratory insufficiency.
Early signs of infantile botulism may be difficulty with feeding since feeding for an infant requires use of the cranial nerves.
Wound Botulism. Wound botulism occurs from the in vivo production of botulinum toxin. It manifests the same neurotoxicity, with the ptosis, bulbar paralysis, and respiratory compromise, as foodborne botulism. Note the profound ptosis in this patient. (Photo contributor: William H. Richardson, III, MD.)