When a child has swollen tonsils and a sore throat that comes and goes for two weeks, it is important to monitor their condition closely. Giving them children's Advil or Motrin can help relieve pain and reduce swelling. Gargling with warm salt water can also help soothe the throat. If the symptoms persist for more than a week or worsen, it may be wise to consult a doctor. It's important to take measures to alleviate the symptoms while waiting for the infection to pass.