thanks for your query,
itching entire body is definitely due to allergy
...Only cause for that is your allergic to either some food or any cosmetics..please try to avoid food which you found to allergic to it..you continue to take that clartin tab or cetrizine
for one month and you will be relieved for sure...If itching is severe take steriod
injection once near by your hospital..Apply liquid paraffin
all over your body..it will reduce your itching soon...
wish you for best health,