Itching is a symptom in hundreds of medical conditions. A definite diagnosis requires a much detailed history than what you have provided. Like since how many days are you suffering from this problem? Is the itching accompanied by redness and swelling? Is itching more at night or daytime? Is it on whole body or any particular part? Is it aggravated by anything? So, please provide us with details or get in touch with a Dermatologist in person.
You can temporarily take tab. Levocetirizine 5 mg SOS to relieve the itch.
Next Steps
Consult a Dermatologist to get a definite diagnosis and cure.