Infections typically begin in the throat or skin. The most striking sign is a strawberry-like rash. Examples of mild S. pyogenes infections include pharyngitis (strep throat) and localized skin infection . Erysipelas and cellulitis are characterized by multiplication and lateral spread of S. pyogenes in deep layers of the skin.
For example, "Strep throat" is often diagnosed within minutes, and is based on the appearance of antigens made by the causative agent, S. pyogenes, that is retrieved from a patient's throat with a cotton swab.