Necrotizing fascitis is caused by -

Ans. is 'b' i.e., Beta hemolytic streptococci The spectrum of infections of the deep soft tissues ranges from localized bacterial, viral and parasitic lesions to rapidly spreading, tissue destructive infections such as necrotizing fascitis and myonecrosis. A) Pyomyositis :- It is common in tropics, therefore also called tropical pyomyositis. It is a localized infection of skeletal muscles. It is caused most commonly by staphylococcus aureus. B) Necrotizing fascitis Necrotizing fascitis is an infection of the deeper layers of skin and subcutaneous tissues, easily spreading across the fascial plane within the subcutaneous tissues. There are two types of necrotizing fascitis :? i) Type 1:- It is a polymicrobial infection, i.e. mixed aerobic and anaerobic infection. It occurs most commonly after surgical procedures in diabetic patients or in those who have peripheral vascular disease. ii) Type 2 :- It is caused most commonly by streptococcus pyogenes (Group A beta hemolytic streptococci). C) Clostridial myonecrosis (Gas gangrene) :- It is characterized by rapid and extensive necrosis of muscle accompanied by gas formation and systemic toxicity. It is caused by C. perfringens (most common), C. novyi, C. septicum and C. histolyticum. It is also called type III necrotizing fascitis.