A child had pustular lesion on leg. On grainstaining gram positive cocci are seen. To establish the diagnosis of Group A streptococcal erythroderma, the test used is: (A) >Bile solubility test, (B) >Catalase test, (C) >Optochin sensitivity, (D) >Bacitracin sensitivity
Answer is D. Bacitracin sensitivity (Ref: Harrison 16thle p 741, Anantnatyan] Streptococcal erythroderma is caused by streptococcus pyogenus Streptococcus pyogenus is b hemolytic streptococci and is Bacitracin positive.