The classic aceteminophen and ibuprofen always work.
In addition, consider using a mixture of diphenhydramine elixer (benadryl syrup) and an antacid (ie Maalox) in a 1:1 mixture by volume and applying it to the painful lesions using a Q-tip. In small children, local application of viscous lidocaine should be avoided.
Source
Knoop, K. MD. Atlas of Emergency Medicine. 2nd ed. McGraw-Hill. 2002.