There are a few options you can try to help relieve seasonal allergies in a child who is experiencing eye itching and excessive nasal congestion. You could consider trying a different antihistamine, such as Claritin or Aerius, as some people respond better to different medications. Additionally, there are over-the-counter eye drops available, such as Cromolyn, which can help alleviate itching when instilled regularly throughout the allergy season. If the issue persists, it may be worth speaking to a doctor about prescription eye drops, such as Pataday, which could also be effective. It's important to address the symptoms to prevent eye infections from excessive itching.