Polyneuropathy and myocarditis are late toxic manifestations of diphtheria. Myocarditis is typically associated with dysrhythmia of the conduction tract and dilated cardiomyopathy. Other complications of diphtheria include pneumonia, renal failure, encephalitis, cerebral infarction, and pulmonary embolism. Neurologic manifestations may appear during the first or second week of illness, typically beginning with dysphagia and nasal dysahria and progressing to other signs of cranial nerve involvement, including weakness of the tongue and facial numbness. Ref: Bishai W.R., Murphy J.R. (2012). Chapter 138. Diphtheria and Other Infections Caused by Corynebacteria and Related Species. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e