Overall mortality is 3%; it is higher in those with any of the following: Delayed presentation Acute renal failure Myocarditis Age < 15 years or > 40 years Diagnosis of Diphtheria Gram stain and culture Pharyngeal diphtheria needs to be considered in patients with nonspecific findings of pharyngitis, cervical adenopathy, and low-grade fever if they also have systemic toxicity plus hoarseness, palatal paralysis, or stridor.