Final answer:
Herpangina, caused by the coxsackie group A virus and presenting with vesicles in the throat, is a self-limiting viral infection that typically clears up within a week with supportive care for hydration and pain.
Step-by-step explanation:
The condition usually caused by the coxsackie group A virus and characterized by vesicles on the posterior oropharynx, resolving within a week, is known as herpangina. This condition primarily affects children and is part of a group of viral infections of the respiratory tract. Though it may cause a high fever, sore throat, and difficulty swallowing, herpangina is most often a mild condition that resolves without treatment. However, supportive care is important and focuses on maintaining hydration and managing pain with analgesics. Like many other viral infections, herpangina is self-limiting and symptoms typically diminish as the body's immune system combats the virus.