Does excitement cause histamine release?

Not usually, but....: The field of psychoneuroimmunology taught us that our immune response can be activated by suggestion -- for example, developing some allergy symptoms when seeing just a picture of a cat (for someone with a severe allergy to cat dander). Typically, histamine is released by mast cells in the presence of antigen-antibody complexes containing antigens interpreted by the immune system as foreign.

Not common, but yes: I had a patient that would get redness, itching, and hives from emotional stress or excitement. It was frustrating and embarrassing for that person. In this case, beta-blockers (a type of blood pressure medicine) helped when Benadryl (diphenhydramine) did not. Adding zantac (blocks a different type of histamine receptor) might help too. Talk to your doctor and ask about that.