Serum Sickness-Like Reaction Associated With Acute Hepatitis B in a Previously Vaccinated Adult Male

Serum sickness is a well-known immune complex deposition phenomenon, occurring as a reaction to proteins in antiserum from a non-human animal source. Serum sickness-like reaction (SSLR), typically associated with drugs and vaccines, sometimes occurs with acute hepatitis B infection and poses a diagnostic dilemma for clinicians, as other viral syndromes, vasculitic processes, and autoimmune conditions can have similar presentations. We present a 36-year-old intravenous drug user, with confirmed records of hepatitis B immunization, who presented with multi-joint pain, joint swelling, and a skin rash. There is a paucity of cases in the literature reporting occurrence of serum sickness-like reaction due to acute hepatitis B infection in a previously fully-immunized adult. This diagnosis should be kept in mind even in the clinical scenario of a fully-immunized patient.