Symptoms usually begin 5-7 days post initial infection and are often nonspecific mailaise and fatigue
Fever of 38°C (100.4°F)
Cyanosis in severe disease
Sore throat ± difficulty swallowing
Hoarseness, cough
Lymphadenopathy
"Bull neck" in laryngeal<unk> 
Dense, grey pseudomembrane covering the posterior aspect of the pharynx
Croup-like cough<unk>  toxin can lead to toxin damage of the heart (myocarditis), nervous system, and kidneys
Myocarditis 
Occurs in 10 to 25% of patients
Typically occurs 7 to 14 days after onset of respiratory symptoms
Heart block, arrhythmias, heart failure, circulatory collapse.
Neurologic toxicity
Occurs in 5% of patients
Local neuropathies are followed by cranial neuropathies
Occurs in 10 to 25% of patients
Typically occurs 7 to 14 days after onset of respiratory symptoms
Heart block, arrhythmias, heart failure, circulatory collapse.
Occurs in 5% of patients
Local neuropathies are followed by cranial neuropathies
Diphtheria
Streptococcal pharyngitis 
Pertussis
Neisseria gonorrhoeae
Plague
Diphtheria 
Anthrax
Bacterial Tracheitis