Small cluster of hives on legs every night but back and back of neck occasionally for months now. Absolutely no signs of bedbugs. Been taking benadryl (diphenhydramine)?

Chronic Urticaria. Chronic idiopathic or spontaneous urticaria (hives) is the persistence of hives on most days of the week for a period of 6 weeks or longer. It is not due to any medication or food trigger. No specific cause can be identified in most patients with this condition. Treatment involves daily doses of non-sedating antihistamines like Zyrtec (cetirizine). See Allergist for more details and treatment options.