Edrophonium: an aid in the diagnosis of acute organophosphate poisoning.

Unsuspected accidental cutaneous exposure to an organophosphate insecticide caused flaccid paralysis in a 10-year-old girl. Electromyogram demonstrated repetitive compound muscle action potentials in response to a single stimulus of nerve; decremental response, more prominent at higher rates of stimulation; worsening of decremental response after edrophonium injection; and normal nerve conduction velocities. Electromyogram with repetitive nerve stimulation and an edrophonium test may provide a simple and rapid method for diagnosis of acute organophosphate poisoning.