Clinically suspected botulism without laboratory confirmation diagnosed through clinical pattern recognition and systematic exclusion

Botulism is a rare but potentially life-threatening neuroparalytic illness caused by inhibition of acetylcholine release at the presynaptic neuromuscular junction, typically presenting with cranial neuropathies followed by descending paralysis and autonomic dysfunction. Diagnosis is primarily clinical because toxin assays are often unavailable, and electrophysiological findings may be non-specific early in the disease. A 27-year-old female developed diplopia, facial weakness, and dysphagia following a gastrointestinal illness, rapidly progressing to respiratory failure. Neuroimaging, cerebrospinal fluid analysis, antibody testing, neostigmine trial, and repetitive nerve stimulation were non-diagnostic. Preserved sensorium, ocular, facial, and bulbar weakness, autonomic features, delayed pupillary constriction, and descending paralysis supported presumptive clinical diagnosis of botulism. The patient required prolonged ventilatory support and tracheostomy, followed by gradual recovery. This case emphasizes systematic exclusion, clinical pattern recognition, and early supportive management when confirmatory testing is unavailable.