Group A hemolytic pharyngitis is due to?
**Core Concept:** Group A hemolytic uremic syndrome (GAHUS) is a rare but severe complication of streptococcal infections, specifically caused by streptococcal pyoderma or erysipelas. Streptococcal infections, in general, are associated with the production of streptokinase, an enzyme that breaks down fibrin in the blood, leading to the characteristic clinical features of streptococcal infections.
**Why the Correct Answer is Right:** Group A hemolytic uremic syndrome (GAHUS) is caused by the production of streptokinase, an enzyme, during streptococcal infections like pyoderma or erysipelas. Streptokinase breaks down fibrin in the blood, leading to the destruction of red blood cells and hemolytic anemia, impaired platelet function, and endothelial dysfunction, which results in thrombocytopenia, microangiopathic hemolytic anemia, and acute kidney injury.
**Why Each Wrong Option is Incorrect:**
A. This option is incorrect because GAHUS is specifically associated with Group A streptococcal infections, not Group B or C infections.
B. This option is incorrect because GAHUS is not caused by streptococcal endocarditis or pneumonia, which are other types of streptococcal infections.
C. This option is incorrect because GAHUS is not associated with streptococcal sepsis, which is a systemic infection involving multiple organs, not specifically the kidneys.
D. This option is incorrect because GAHUS is not caused by streptococcal bacteraemia, which refers to the presence of streptococcal bacteria in the bloodstream, not the specific syndrome resulting from streptococcal infections.
**Clinical Pearl:** The correct answer, Group A hemolytic uremic syndrome, is a severe complication of streptococcal infections, particularly pyoderma and erysipelas. It is caused by the production of streptokinase enzyme, which leads to the characteristic symptoms of hemolytic anemia, thrombocytopenia, and acute kidney injury. This condition is a reminder of the importance of diagnosing and treating streptococcal infections promptly to prevent severe complications.