Arcanobacterium hemolyticum infection: confused with scarlet fever and diphtheria.

Arcanobacterium hemolyticum infections are a common cause of pharyngitis and rash in the 10- to 30-year-old age group. Despite its prevalence, many emergency and primary care physicians may not be aware of the pathogenic potential of this organism. We present a case that illustrates the distinctive clinical spectrum of A. hemolyticum infections that may be confused with drug allergy, group A streptococcal scarlet fever, diphtheria, and even toxic shock syndrome. Recognition of this syndrome will reduce misdiagnoses and facilitate appropriate treatment.