Published online Mar 7, 2015. doi: 10.3748/wjg.v21.i9.2826
Peer-review started: August 8, 2014
First decision: September 27, 2014
Revised: November 2, 2014
Accepted: December 1, 2014
Article in press: December 1, 2014
Published online: March 7, 2015
Processing time: 214 Days and 8.9 Hours
Peginterferon is a key drug used to treat chronic viral hepatitis that is known for causing various side effects. Side effects occurring immediately after administration include headache, nausea, and influenza-like symptoms, such as fever and joint pain. However, reports of anaphylactic shock are extremely rare. Here we report a patient with protracted anaphylaxis who suffered shock symptoms after peginterferon α-2a administration for chronic hepatitis C. Although the patient improved temporarily with shock treatment, symptoms of anaphylaxis recurred. As peginterferon is often administered on an outpatient basis, it is important to recognize life-threatening side effects that may develop in a protracted manner.
Core tip: This is the first report that describes a case involving anaphylactic shock that developed after peginterferon administration. Moreover, our case showed protracted anaphylaxis, in which symptoms appear hours after exposure to the causative substances and temporarily improve with treatment but recur twice within hours. Protracted anaphylaxis is rare; its incidence accounts for less than 20% of all cases of anaphylaxis. There are few case reports regarding this condition, and its pathophysiology has not yet been established.