Hello - there are a variety of different causes for hives, not all of them are due to allergies. If you have an abnormal
complete blood count, as you described, the next step should be to have a peripheral smear done. This is like a CBC except instead of an automated cell counter, a trained lab worker actually looks at the cells for abnormal shapes, etc. In particular, there should be further investigation into your low white blood count.
In addition, a
thyroid test is recommended when there is itching or hives: TSH and
thyroxine levels.
Allergies to particular foods, to cosmetics, soaps, lotions, laundry products, and things you are exposed to, can also cause recurring hives.
If your primary doctor isn't looking into it, then see a
dermatologist or an allergist for further work up.
Medications that are commonly used for recurring hives include Zyrtec in higher dosages than usually prescribed for nasal allergies, and sometimes if hives continue, alternate drugs such as
gabapentin.