Rheumatoid Arthritis-like Disorder Mimicking Serum Sickness: Do Not Forget Acute B Hepatitis

We report on a patient who presented with a severe symmetric polyarthritis that was found to be part of the prodromal stage of acute hepatitis B. This syndrome is seen in a minority of cases, resembles serum sickness and parallels the duration and level of hepatitis B viremia. It is a type III immune complex reaction with complement consumption and activation which ultimately triggers inflammation and may also occur in the context of other infections, vaccines, and use of antibiotics or sera. We emphasize the need to search for acute B hepatitis in all patients with polyarthritis or other symptoms of serum sickness.