Hi,
Chronic idiopathic hives are red, itchy skin welts which persists more than 6 weeks. It's probably resulted from a combination of factors like environmental irritants, body's immune system, genetics, a response to a bacterial, viral or 
fungal infection. Avoidance of triggering factors is the primary prevention of 
chronic idiopathic urticaria. Antihistamines like Fexofenadine, Loratadine, Desloratadine etc., that don't make someone drowsy, are the standard treatment for chronic idiopathic urticaria.
But, for patients whose urticaria is unresponsive to antihistamines, then leukotriene receptor antagonists like Montelukast, steroids like 
prednisolone, 
sulfasalazine and a host of immuno-suppressives like 
Methotrexate, Cyclosporine, Omalizumab etc., can be used to treat chronic idiopathic urticaria. If you experience any complications during using prednisolone then you can use Omalizumab called Xolair shot, which will be a safe and effective option for your chronic idiopathic urticaria.
Take care. Hope I have answered your question. Let me know if I can assist you further.
Regards,
Dr. Zubayer Alam, General And Family Physician