Hello and welcome to HCM Cetrizine will help if your itching is due to allergy. It is usually safe and causes only mild drowsiness. The most important thing is for you to find out the cause of the itching. When did it start? is it the first time? Do any family members,kids or contacts have similar complaints? Have you had any allergies in the past, to food, any medicines, seafood, pets, dust, sun ,etc? if you have any such history it is important to avoid these factors completely. Also certain infection and infestations with mites in the skin can cause severe itching.This will need to be seen by a dermatologist to diagnosis. Also you have not mentioned your age or any other illnesses or medicines you are on. You may need to check your sugar levels, thyroid hormones etc. Till then continue another allergy drug such as fexofenadine and apply calamine lotion. But do see the dermatologist for a long term solution. Also they can advise you allergy tests to find out the cause for you. Hope this helps you.