A 2 year old male child was brought to me with complaint of fever high grade, cough, cold for 4 days. Started him on ceftriaxone 250 mg inj, paracetamol, and cetrizine syrup. Child became well in 4 days. After 7 days the child was brought with complaint of urticarial rashes on most part of body and swelling bilateral lower limbs.

His serum albumin is within normal. TLC- 15400, N46 L54. What is the diagnosis? I gave steroid, antiallergic, and mox-clav.