Scarlet fever is caused by -

Ans. is 'b' i.e., Streptococcus pyogenes Infections caused bv streptococcus pyogenes1) Respiratory infectionso Sore throat is the most common of streptocococcal disease. It may be localised as tonsillitis as in older children and adults or it may involve the pharynx more diffusely (pharyngitis) as in younger children,o Otitis mediao Mastoiditiso Quincyo Ludwig's anginao Suppurative adenitiso Pneumonia as a complication of influenza or other respiratory viral disease.Skin and soft tissue infectionso Erysipelas- Diffuse infection involving the superficial lymphatics.- Occurs in older patients.o Impetigo- Superficial infection of skin(Pyoderma)- Occurs in young patients- Usually involves face and leg.o Cellulitiso LymphangitisDeep soft tissue infectionso Necrotizing fascitis (hemolytic streptococcal gangrene)o Myositis - (Most common organism causing myositis is S. aureus)Abscesses - in brain, lungs, liver, and kidney.Scarlet fevero Consists of pharyngitis, accompanied by a characteristic rash,o Caused by production of erythrogenic toxin.Puerperal sepsiso More often caused by group B streptococci.BacteremiaStreptococcal toxic shock syndromeo Str. Pyogenes strains M type 1 and 3 forming pyrogenic exotoxin A are responsible,o These strains also known as [flesh eating bacteria \Nonsuppurative complicationso Acute Rheumatic feverFollows persistent or repeated streptococcal throat infections (not skin infection).o GlomerulonephritisMay occur after throat or skin infection perhaps, in the tropics skin infections are more important than throat infections.