Safety of quick fix for insect stings investigated
April 2nd, 2012
A group of scientists and clinicians studying people's allergic reactions to insect stings has found that fast immunotherapy treatments for patients seeking protection from anaphylaxis are convenient, but may not be as safe as slower methods.
Professor Simon Brown, a researcher with the Harry Perkins Institute of Medical Research headed a team from Perkins and the Royal Hobart Hospital (RHH) in Tasmania that conducted a controlled trial into Venom Immunotherapy Treatment (VIT) specifically aimed at people allergic to the Australian jack jumper ant.
"Traditionally, VIT starts with very small doses of venom extract injected under the skin of people known to have allergic reactions to insects. These doses are gradually increased (semirush approach) until the individual becomes desensitised so that he or she no longer reacts if accidentally stung by an ant," Professor Brown explained.
"Rapidly increasing the dose over 1 day (ultrarush treatment) has been regarded as safe and more convenient, but we wanted to compare this to the slower approach, as this has never been done before," he said.
In the trial, published by The Journal of Allergy & Clinical Immunology (JACI), Professor Brown directly compared ultrarush VIT with the slower semirush approach in patients with a history of anaphylaxis to Australian jack jumper ant stings.
93 patients were randomly given semirush or ultrarush schedules. The authors also compared an additional 89 patients who chose which approach they preferred.
"We found that allergic reactions to VIT were more likely during the faster, ultrarush initiation (65% versus 29%)," Professor Brown said. "Severe, potentially life-threatening allergic reactions were also more common (12% versus 0%). This challenges the view that fast methods of VIT are as safe as slower ones."
Professor Brown said that a greater risk of allergic reactions, including severe hypotensive reactions, with ultrarush VIT may be particularly important in patients of advanced age, when a severe reaction could be life-threatening.
Royal Hobart Hospital CEO, Jane Holden said the Jack Jumper Allergy Program established by Professor Brown had played a leading role in a number of landmark studies in the field of allergy and anaphylaxis.
"Insect venom allergy is a significant clinical problem in Tasmania, affecting more than 3% of the population" Ms Holden said. "We are proud to be able to provide world-class clinical care to the people of Tasmania who have life-threatening allergy to insect stings, and to be able to participate in internationally significant and practical research efforts to improve the clinical care of these people".
The Journal of Allergy and Clinical Immunology (JACI) is the official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.