Local Blistering Reaction Complicating Subcutaneous Injection of Pegylated Interferon in a Patient with Hepatitis C

PEG-Intron is a covalent conjugate of recombinant alpha-2b interferon with monomethoxy polyethylene glycol (PEG). Compared to standard interferon-alpha injections, this preparation has a longer half-life allowing for onceweekly injections and superior antiviral efficacy in the treatment of hepatitis C when used in combination with ribavirin. We report the first case of a local blistering reaction developing in a patient receiving pegylated interferonalpha- 2b. Previous reports of local cutaneous reactions to standard and pegylated interferon-alpha are reviewed and the pathophysiological mechanisms are discussed.