Ms. Mary Chiles, a 23-year-old nurse, has developed a skin rash as well as nausea and vomiting, after taking an antibiotic drug for a short time. The skin rash is red and quite itchy and is spreading throughout her body. Her physician, Dr. Matthew B. Smith, tells her to stop the antibiotic medication immediately and asks her to see him as soon as possible for further check-ups. Ms. Mary tells Dr. Smith that she has had a history of skin rash, both eczema and contact dermatitis, since infancy. She has had hay fever during the hotter months for the past several years.
Why would her physician consider this an allergic reaction to the antibiotic?
What kind of hypersensitivity is hay fever and what are its signs and symptoms?