My girlfriend have hives, but is allergic to benadryl (diphenhydramine). what can she do?

Many options.: It would be unusual to be truly allergic to an allergy medication, but assuming this is correct, options include other antihistamines (claritin, allegra, zyrtec) or oral steroids. If one is experiencing nasal symptoms, there are a variety of prescription nasal sprays that can also be very helpful. Best to consult with your doctor to see which options are best.