Thank you for your inquiry.
As you know, the discussion over the waiting period for an allergy injection is one which has been pervasive throughout the many years that we have been concerned about fatalities. The issue has been deliberated on a number of occasions, and I am sure intensely deliberated during the development of the Guidelines.
In my opinion, there is no definitive “correct” answer as to how long a patient should wait after an injection. The issue is always going to be resolved with compromise between practicality and safety. I personally believe that the authors of the most recent Guidelines Parameters) have done about as good a job as one can in regards to this issue. I think that your protocol is certainly well thought out and would be a competitor amongst the many suggested wait periods that have been bantered about over the years.
This venue, however, is not the appropriate “battleground” for this issue, and your suggestion, well presented, would be best handled by the Joint Task Force which is in charge of the construction of all of our Guidelines. My voice, added to the polemics, I think would create more smoke than fire. Therefore I am going to pass your suggestion on to Dr. Linda Cox, the lead author of the most recent Guidelines, who I feel sure will be a prominent force in any new Parameters. I think this would be the proper direction for your suggestion.
Thank you again for your inquiry.
Phil Lieberman, M.D.
We have received a response from Dr. Linda Cox. Thank you again for your inquiry.
Phil Lieberman, M.D.
Response from Dr. Linda Cox:
Several recent surveys have demonstrated a fairly significant number of SR occurring outside of the 30 minute period. Some of them were conducted (I think) with the hopes of supporting the argument for a shorter wait but instead provided some evidence to suggest a long longer wait. I know Jim Sublett's group and Chuck Siegel have looked at this. Jim said their study supports a 30 minute wait because this is when all or almost the serious SR have occurred. This is also consistent with David Lang's study.1 Although they had a fairly high >30 minute SR rate, all serious SR occurred within 30 minutes and they determined this was the optimal wait period. Dick Lockey's group's 1 year prospective study reported 22% of SR occurred beyond 30 minutes and one was a e WAO grade 4 SR (paper attached). Last the 4 year AAAAI/ACAAI AIT safety study found 14% of SR occurred beyond 30 minutes.2
This will certainly be a topic of discussion during the next Allergy Immunotherapy Practice Parameter update, but the debate will likely focus on what recommendations should be provided for these >30 minute SR (i.e .to prescribe epinephrine autoinjectors or not). I doubt with all these recent studies, the JTF would consider shortening the wait period recommendation.
In response, to his suggested proposal-longer wait for patients with prior SR doesn't help the first SR. I also think it is a little complicated in terms of implantation. Patient and staff get used toa protocol or system and it changes under various circumstances eg new vial, skipped dose-it could be confusing
DaVeiga SP, Liu X, Caruso K, Golubski S, Xu M, Lang DM. Systemic reactions associated with subcutaneous allergen immunotherapy: timing and risk assessment. Ann Allergy Asthma Immunol. 2011;106(6):533-7 e2.
Background: Subcutaneous allergen immunotherapy (SCIT) is associated with risk of systemic reaction. Although risk factors have been identified, the incidence of immunotherapy-related systemic reactions has not changed in recent years.
Objectives: To examine patterns of systemic reaction and determine whether risk of systemic reaction from SCIT is associated with patterns of response to skin tests to inhalant allergens recorded before receiving SCIT.
Methods: We carried out a retrospective review from January 2001 to December 2007. Patterns of systemic reaction from immunotherapy were examined. Cases were matched with controls by age (+/-10 years), sex, and time of injection (+/-1 week) to determine whether a pattern of more than 33% 3+ and 4+ skin test responses is associated with elevated risk for systemic reaction.
Results: Rate of systemic reaction from SCIT was 0.28% (46/16,375) per injection visit. Twenty patients had 46 systemic reactions. All severe reactions occurred within 30 minutes. The estimated odds of systemic reaction were almost 6 times higher for patients with more than 33% 3 to 4+ positive skin tests (OR = 5.83; 95%CI: 1.23-27.59, P = .026). For each additional 4+ skin test, the estimated odds for systemic reaction increased by 17% (P = .020).
Conclusions: A small number of patients receiving SCIT account for a large proportion of systemic reactions. Skin test patterns demonstrating a greater number of larger skin tests responses to inhalant skin testing are associated with significantly elevated risk for systemic reaction in patients receiving SCIT.
Epstein TG, Liss GM, Murphy-Berendts K, Bernstein DI. Immediate and delayed-onset systemic reactions after subcutaneous immunotherapy injections: ACAAI/AAAAI surveillance study of subcutaneous immunotherapy-year 2. Ann Allergy Asthma Immunol. 2011;107(5):426-31
Background: Incidences of subcutaneous immunotherapy (SCIT) related systemic reactions (SRs) and fatal reactions (FRs) are not well defined, nor are delayed-onset SRs and their treatment.
Objectives: To estimate SCIT-related SRs/FRs, and the incidence and treatment of delayed-onset SRs.
Methods: In 2008 and 2009, American Academy of Allergy, Asthma & Immunology (AAAAI) and American College of Allergy Asthma & Immunology (ACAAI) members completed a survey about SCIT-related SR severity (grade 1 = mild; grade 2 = moderate; grade 3 = severe anaphylaxis). In 2009, members reported the time of onset and use of epinephrine (EPI), with early onset defined as beginning< /=30 minutes, and delayed onset beginning more than 30 minutes after injections.
Results: As in year 1, no FRs were reported during year 2 (630 total practices responded). Among 267 practices providing data on the timing of SRs, 1,816 early-onset SRs (86%) and 289 (14%) delayed-onset SRs were reported. Fifteen percent (226/1,519) of grade 1, 10% (54/538) of grade 2, and 12.5% (9/72) of grade 3 SRs were delayed-onset. Among early-onset SRs, EPI was given for 71% of grade 1, 93% of grade 2, and 94% of grade 3s. Among delayed-onset SRs, EPI was given for 56% of grade 1, 67% of grade 2, and 100% of grade 3s (P = .0008 for difference in EPI administration based on severity; P = .07 based on time of onset).
Conclusions: Delayed-onset SRs are less frequent than previously reported. Epinephrine was given less frequently for grades 1 and 2 (but not grade 3) delayed-onset SRs compared with early-onset SRs. Further study of prescribing self-injectable EPI for SCIT patients in the event of delayed-onset SRs may be warranted
Systemic reactions to subcutaneous allergen immunotherapy and the response to epinephrine.
1. DaVeiga SP, Liu X, Caruso K, Golubski S, Xu M, Lang DM. Systemic reactions associated with subcutaneous allergen immunotherapy: timing and risk assessment. Ann Allergy Asthma Immunol 2011;106:533-7 e2.
2. Epstein TG, Liss GM, Murphy-Berendts K, Bernstein DI. Immediate and delayed-onset systemic reactions after subcutaneous immunotherapy injections: ACAAI/AAAAI surveillance study of subcutaneous immunotherapy-year 2. Ann Allergy Asthma Immunol 2011;107:426-31 e1.