Huangshi Xiangsheng Ertong Spray

Primary objective: To investigate whether the pain-free rate after 3 days of treatment with Huang's Sound Spray (Children's Type) is different from that of placebo in participants with acute pharyngitis (exogenous wind-heat syndrome) whose pharyngeal pain (dynophagia) is as severe as 4 points on the WBS. Secondary objectives: (1) To evaluate the effect of Huang's Sound Spray (Children's Type) on the changes in symptoms and signs of participants with acute pharyngitis (exogenous wind-heat syndrome); (2) To evaluate the safety of Huang's Sound Spray (Children's Type) in the treatment of acute pharyngitis (exogenous wind-heat syndrome).