Final answer:
The patient's symptoms of fever, urticaria, and polyarthralgia without mucosal involvement suggest a serum sickness-like reaction. Serum sickness is a type III hypersensitivity reaction that occurs a few weeks after exposure to certain medications such as penicillin or Bactrim.
Step-by-step explanation:
The patient's symptoms of fever, urticaria (hives), and polyarthralgia (joint pain) without mucosal involvement suggest the possibility of a serum sickness-like reaction (option a). Serum sickness is a type III hypersensitivity reaction that occurs a few weeks after exposure to certain medications such as penicillin or Bactrim. It is characterized by the formation of immune complexes that deposit in various body sites, leading to symptoms such as fever, rash, vasculitis, and arthritis. It can also involve other organs like the kidneys and liver. Other options like anaphylaxis, drug-induced lupus, and Steven-Johnson syndrome do not match the given symptoms.