My daughter in law is 25, yesterday she was vomiting and had diarrhea which resolved but today she is still nauseous and broke out in welts bilaterally on her arms, hips. The welts itch, they improved with Benadryl this afternoon but have noe returned. She has a history of rather odd reactions to cold, heat and bug bites, any thoughts if the welts are related to yesterday s illness or possibly two separate issues?