<prompt> Peritonsillar abscess is most commonly caused byStreptococcus pneumoniaStaphylococcus aureusBeta hemolytic streptococcusHemophilus influenza  <response>: Peritonsillar abscess Quinsy is the collection of pus in the peritonsillar space which lies between the capsule of tonsil and superior constrictor muscle. A peritonsillar abscess usually follows acute tonsillitis. First crystal Magna is infected and sealed off. Culture of pus from the abscess May reveal beta-hemolytic streptococci, S.aureus, or anaerobic organisms. Ref: Diseases of ENT, PL Dhingra, 7th edition, pg no.298 