Seems like a Chronic Spontaneous Urticaria. Assuming this diagnosis, Levocet needs to be consumed for atleast 3-6 months.
It is a safe medication and can even be used long-term without significant side effects.
Next Steps
Consult a General Physician / Dermatologist for proper diagnosis and management.
Health Tips
1. You need to actively look out for any triggers/allergens eg dust, sunlight, cold, or heat to bring itching under control.
2. Avoid scratching your skin too much as it can lead to thickening/lichenification, which would be difficult to treat.