Hello, Thank you for asking at HCM. I carefully read your question and understand your concern. If your son is having hives it is most likely something is causing him a reaction- allergy. It is very difficult sometime to find the cause of it. Can be food, detergents, parfumes, flowers, environment agents ect and the multitude of agents make it hard to find what might be the cause. Warm baths might make the itchiness worse due to increase of blood flow locally so i would recommend to not have frequent or prolonged baths at this time he has the hives. Benadryl is good but he needs to take it three times a day regularly. It will make him a little sleepy and help with itchiness also. You can start to avoid fist agents that you highly suspect are causing him the symptoms and wait for some days for an effect- sometimes it takes several days for the reaction to subside even when the causing agent is avoided. If not able to determine the cause than allergy skin tests can give some help and try to identify the cause. If your son gets eyes or lips swollen or gets short of breath this is a more serious allergic reaction and he needs to be sent urgently to the emergency department. Hope this is helpful and answers to your question