- Streptococcus pyogenes is the causative agent of scarlet fever, characterized by the classic "strawberry tongue" due to inflammation and desquamation of the tongue's papillae.
- Additionally, it can trigger rheumatic fever, an autoimmune complication resulting from molecular mimicry between streptococcal M proteins and host tissues.
- Neither Staphylococcus aureus, Corynebacterium diphtheriae, nor Haemophilus influenzae cause this specific clinical syndrome or rheumatic fever.
- This makes Streptococcus pyogenes the correct and sole responsible microorganism for these presentations.

Reference: Harrison’s Principles of Internal Medicine, 20th Edition, Infectious Diseases Chapter, p. 1113