To deal with the pain caused by sores on your hands, feet, and mouth, you may also want to take an over-the-counter pain reliever such as ibuprofen or acetaminophen.  Check with your doctor if you are not sure how much to take or how much to give your child. Make sure that you check the package instructions as well and follow them carefully. Do not give aspirin to children because it can cause a rare, but life-threatening condition called Reye's syndrome. A pain relieving gel may also help to make sores on your mouth a bit more bearable. Look for a topical pain relieving gel that is safe to use on your mouth and follow the package instructions for use. Chamomile tea has soothing and antiviral properties, so it may help to support healing of the sores caused by hand, foot, and mouth disease. To use chamomile tea, brew a cup of chamomile tea and allow it to cool down to room temperature. Then dip a cotton ball into the tea and use the cotton ball to dab a bit of tea on you sores. You can also use elderberry juice or tea, which may be a better option for kids because of the flavor. Elderberry also has antiviral properties. Gargling with some warm, salty water a few times per day may also help to relieve the pain caused by sores in your mouth and throat. Heat up some water so that it is warm but not hot. Then, add a teaspoon of sea salt to the water and stir the water until the salt has fully dissolved. Swish a mouthful of this water for about 30 seconds. Repeat throughout the day to help with pain.

Summary:
Take an over-the-counter pain reliever. Use a topical pain reliever. Dab chamomile on sores. Gargle with warm saltwater.