The severity of illness varies from a mild condition to a very serious disease with death within 24 hours. The initial symptoms are usually those of motor cranial nerve involvement with onset of diplopia, dysphonia, and dysphagia. A generally symmetric descending paralysis follows. Abdominal pain, with nausea and vomiting may precede or follow paralysis. A dry mouth and throat reflect cholinergic parasympathetic disturbance.
Patients generally remain alert and responsive.
Sensory deficits, besides blurred vision, have been reported only in rare cases. The incubation period averages about 7 days. Wound botulism may occur in any wound contaminated by soil or water. Symptoms are generally the same as those seen in food-borne botulism, except gastrointestinal symptoms are absent. The source wound may appear relatively benign.