Does benadryl (diphenhydramine) help contact dermatitis rash go away or does be benadryl (diphenhydramine) only help with itching not the swelling?

Contact dermatitis: Benadryl (diphenhydramine) and other antihistamines treat reactions that are cause by histamine release, like hives (urticaria). Contact dermatitis is inflammation driven by cells of the immune system called lymphocytes. Taking Benadryl (diphenhydramine) for contact dermatitis will make you sleepy but doesn't reduce itch or inflammation. Contact dermatitis responds to topical and if severe enough, oral steroids.