Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain crazy itchy tongue that gets relieved with medication but recurs after the medication is stopped is clearly pointing towards a severe
allergic reaction to some unknown allergen and can be most probably and food or medication...
I would suggest you to consult an Allergist and get allergic tests like
Patch test, RAST test, food challenge test etc can help in diagnosis and treatment can be done accordingly..
The tests will help in ruling out the exact cause of the allergen and once you know the cause of the allergic reaction you can avoid exposure to it to prevent allergy attack..
He can be advised to take anti allergics like
benadryl along with
steroid nasal sprays to relieve the symptoms..
He can also be instilled an
Immunotherapy that will help in reducing the severity and frequency of allergic attack..
Once the allergen is ruled out avoiding exposure to it can prevent the allergy symptoms..
Hope this information helps..
Regards..