<prompt> Erysipelas is a skin infection often caused byErysipelothrix rhusiopathiaeStreptococcus pyogenesPseudomonas aeruginosaTrichophyton rubrum  <response>: STREPTOCOCCAL INFECTIONS Gram-positive bacteria arranged in chains or pairs . Not pa of normal cutaneous flora but resident of aerodigestive tract and vagina. Classification two methods: a Ability to induce hemolysis a, b, g andor b Lancefield groups A-D, G based on characteristic polysaccharide cell wall Of note, group A b-hemolytic streptococci S. pyogenes, GAS most pathogenic. Erysipelas St. Anthonys Fire:- Superficial type of cellulitis with significant dermal lymphatic involve-ment; typically due to GAS. Presents as a well-defined, bright red indurated plaque with sharp, raised borders commonly on the face or legs, - constitutional symptoms. Treatment of choice:- Penicillin PCN if PCN allergic can use macrolide. Ref:- Sima Jain; pg num:-206 