The conjunctiva may become necrotic, and thrombosis of perilimbal vessels can lead to corneal ulceration and scarring and to corneal perforation from corneal ischemia. Local paralysis of the soft palate and posterior pharyngeal wall are most common with other cranial neuropathies leading to oculomotor and ciliary paralysis, and facial and laryngeal weakness. Peripheral neuropathy may occur 10 days to 3 months postinfection, with proximal motor neuropathy initially, then moving distally, commonly involving dorsiflexors of the foot. Oculomotor palsy and abducens palsies may be unilateral, bilateral, complete, or incomplete. Facial nerve paralysis may cause difficulties with eyelid closure.
Pupillary reactions remain normal.
Usually, resolution of these cranial neuropathies occurs spontaneously within 2-6 weeks. Diphtheria is an acute infectious disease caused by the gram-positive bacillus Corynebacterium diphtheriae. Treatment includes supportive care and isolation and penicillin or erythromycin, which are extremely effective against C diphtheriae. Diphtheria antitoxin, a hyperimmune antiserum produced in horses protects against neurotoxicity when given within the first or second day of the illness. Prevention is accomplished by immunization with formalin-inactivated toxin, usually given within the first year of life.