My daughter has large colorless welts all over her back, behind her knees and on her elbows. She s experiencing intermittent nausea and dizziness that is alleviated when she sits. The welts do itch in spots. She also has a painful bump on the ball of her foot that hurts to walk on. Although probably unrelated to the other symptoms, it appeared suddenly as did these welts. Is this an allergic reaction? She has not been exposed to nor eaten anything out of the ordinary.