CRITICAL DECISION

What clinical clues suggest the diagnosis of botulism?

The incubation period of infantile (intestinal) botulism is nearly impossible to pinpoint. Constipation is often the initial symptom and can be present for days before neurologic symptoms occur.² Cranial nerves are affected first, resulting in the loss of facial expression and decreased suck and cry. Initially, these findings are very subtle. As neurologic deterioration continues, the baby will develop poor head control and diffuse hypotonia (“floppy baby”).⁴ Symptoms progress over hours to days (mean of 4.2 days) before the child is hospitalized and the disease is recognized.⁵ As in adults, respiratory paralysis is responsible for botulism mortality. Infantile botulism is thought to be an occasional etiology for sudden infant death syndrome.⁵

Food-borne and wound botulism have indistinguishable symptoms. The incubation period for food-borne botulism is between 12 and 72 hours.¹ Determining a precise incubation period for wound botulism is difficult, if not impossible. Symptoms of both conditions usually start with cranial nerve deficits: Diplopia, facial weakness, dysphagia, ptosis, and speech changes are all common findings. Paralysis then descends, affecting the upper extremities before the lower. Respiratory muscle paralysis occurs as the process descends. The autonomic nervous system is also affected, resulting in dry mouth, postural hypotension, paralytic ileus, and pupillary abnormalities.

In one emergency department case series of food-borne botulism, all 29 patients had at least three of the following: weakness, dry mouth, double vision, and difficulty speaking.⁸ In a larger case series of 705 patients, 68% had at least three of the following symptoms on admission: nausea and vomiting, dysphagia, diplopia, dry mouth, and fixed and dilated pupils.²

CRITICAL DECISION

Are there any confirmatory tests for botulism that can be performed in the emergency department?

In all three varieties of botulism, the diagnosis is clinical. Stool, wound, and blood should be tested for toxin and cultured. However, these are of no help in the emergency department diagnosis and management of the condition. Routine diagnostic studies are helpful only to rule out other conditions. The best way to confirm the diagnosis of infantile botulism is through identification of the toxin in the stool, which may be difficult, as these patients are usually very constipated.⁵

CRITICAL DECISION

What immediate life threats must be addressed in a patient with botulism?

All patients with suspected botulism should be admitted to the ICU for observation and supportive care. The primary concern is the evaluation and management of the patient’s airway and respiratory status. If there is any concern for airway or respiratory compromise, the patient should be immediately intubated and maintained on mechanical ventilation until the toxin’s effects have worn off, which can take weeks. Even if the patient’s respiratory status is good on initial evaluation, it must be reassessed frequently, because this disease can progress rapidly.

CRITICAL DECISION

Other than supportive care, what can be done for a patient with botulism?

In addition to supportive care, all patients with food-borne and wound botulism should be treated with one vial of botulism antitoxin.1 Because this is derived from horse serum, all patients should have skin testing for hypersensitivity before administration. The antitoxin has been shown to decrease mortality and reduce hospital length of stay. Although it prevents progression of the disease, it does not reverse the paralysis, as the toxin binds irreversibly. The antitoxin can be obtained through state and local health departments and the CDC.¹