Pathology · single question
Scarlet fever is caused by which organism?
Show answer and explanation
Correct answer: D. Streptococcus pyogenes Group A (via erythrogenic toxin)
- A. Streptococcus viridans is associated with infective endocarditis — not scarlet fever.
- B. Staphylococcus aureus produces toxins causing scalded skin syndrome and toxic shock syndrome — not scarlet fever.
- C. Streptococcus pneumoniae causes pneumonia, otitis media, and meningitis — not scarlet fever.
- D. Correct. Scarlet fever is caused by Group A Streptococcus (Streptococcus pyogenes) strains that produce erythrogenic exotoxin (pyrogenic toxin). Clinical features: sore throat, fever >101°F, 'sandpaper' skin rash, strawberry tongue, and Pastia's lines in skin folds.