<prompt> A previously healthy eight year old boy presented to the emergency depament with high grade fever, ahralgia, pruiritic erythematous rash and lymphadenopathy. He had completed 8 days out of a 10 day course of cefaclor for an upper respiratory tract infection. Which of the following possibilities should be initially suspected?Kawasaki DiseaseAnaphylaxisHenoch Schonlein purpuraType III Hypersensitivity Reaction  <response>: Boy in the questions who developed the fever, rash, lymphadenopathy, after taking cefaclor for UI is suffering from drug induced serum sickness. Its a type 3 hypersensitivity mediated by IgG antibody. Ref: Essentials of emergency medicine By Richard Aghababian page307; What to do About Allergies By Harvard Health Publications page 8. 