Treatment is available for kids with cold sores. Start with cold liquids, ice, or frozen juice bars to help soothe mouth pain. Avoid giving children spicy or acidic foods (e.g., citrus fruits or tomato sauce). For lasting relief of pain and itching associated with kids cold sores, use over-the-counter topical medicine Blister Balm External Analgesic Ointment. A unique 100% naturally medicated effective and immediate cold sore treatment for kids 2 years of age and older.