Just because an allergist can't find a specific allergy that you have does not mean that it is not some allergy.
They can do panels to check the blood for antibodies against common allergens and they can do more detailed analysis with skin testing. However while they can test for hundreds of possible suspects there are millions in nature and your particular allergy may be unique.
Your CBC(complete blood count) may have been checked and if so it may have shown a high eosinophil count if indeed your have chronic urticaria(hives) due to allergies.
Your doctor may also check your IgE level which is an antibody subtype that is specific to an allergic reaction.
The reaction that you are dealing with may be caused also at times by autoimmune disease. (systemic lupus, autoimmune thyroid disease, polycythemia vera)
IN some patients certain physical stimuli can cause this problem. Cold, exercise, heat/sun.
Allergy sources may include foods, drugs, inhaled (pollen, mold spores, animal dander)
Your allergist probably ruled out the most common ones but it is imppossible to rule out all. I would recommend that you keep a diary of when your symptoms occur along with your diet and activities and where you are. There may be important clues in the pattern.
With the liver disease a person may have itching without a rash that is related to this (generally related to high bilirubin levels) but your hives are probably not due to liver disease.
The Zyrtec and Hydroxyzine are good treatment options. The Zyrtec is good for AM and taken once a day. Zyrtec would be less likely to make you drowsy. Hydoxyzine (or benedryl 25 to 50 mg) may be taken if you have a flare up or at bedtime if this helps. There is nothing wrong with taking say the Zyrtec daily or a combination if this controls the symptoms. I have seen several patients whom have had chronic urticaria with undetermined cause in which this worked well. (They won't hurt you to take long term)
If these do not control the hives (all the meds mentioned above are H-1 type anti-histamines) then you may add an H-2 type anti-histamine to increase their effectiveness.This would include Zantac 75 to 150mg twice a day if needed. (75mg tablets are over the counter and the 150mg tabs are available by prescription) Pepcid and Tagamet are other examples of this class.
You may benefit to also consult a dermatologist as they would frequently deal with this problem.
I hope this information helps. If you should have further questions then let me know and I will be happy to get back with you. If my answer has been helpfula nd to your satisfaction then please remember to press the "ACCEPT" button. Thank you and Best Regards,
Anthony Bray MD