Systemic reactions to subcutaneous allergen immunotherapy and the response to epinephrine

Abstract

The use of epinephrine for anaphylaxis to subcutaneous allergen immunotherapy (SCIT) is the standard of care, but its use for mild systemic reactions (SRs) is somewhat controversial. The objective of this study is to determine the rate of SR to SCIT, the symptoms reported, and the response to intramuscular (i.m.) epinephrine over a 1 year period. This retrospective study was designed to evaluate SRs to SCIT to any combination of approximately 20 allergens (pollens, animal emanations, molds, and Hymenoptera) in 773 subjects representing 14,707 visits, receiving approximately 28,000 injections over 1 year. Nurses were instructed to administer epinephrine (1:1000 v/v) 0.2 mL i.m. for signs or symptoms of a SR. SRs were graded using the universal grading system proposed by the World Allergy Organization (WAO) Joint Task Force for Grading SR to Immunotherapy. Thirty-one patients (4%) had 32 SRs, 22 (71%) female, average age 40 yr. Nineteen (61%) had a history of asthma; 7 (22.6%) had a history of a previous SR. SRs were reported on average 24 minutes after injection. Symptoms included: generalized pruritus, 34.4%; upper airway pruritus, 28.1%; cough, 25.0%; shortness of breath, 21.9%. Fourteen SRs were classified as Grade 1, thirteen Grade 2, two Grade 3, and three Grade 4. No Grade 5 or late phase reactions were reported. 29 (90.6%) reactions were treated with epinephrine, 27 (84.4%) glucocorticosteroid, and 30 (93.8%) H1 antihistamine. SRs occurred in 4% of patients receiving SCIT and all who received early intervention with epinephrine responded successfully. The WAO Grading system was useful.

The safety of self‐administered allergen immunotherapy during the buildup and maintenance phases

“…To the best of our knowledge, this is the largest study reporting the safety outcome of a self‐administered SCIT protocol for a patient cohort consisting of tens of thousands of individuals. The UAS SR rates are significantly lower than those promulgated for traditional in‐office IT protocols ( p < 0.0001) . No grade V anaphylactic reactions occurred in over 2 million home‐administered injections.…”

Predictive Factors for Clinical Response to Allergy Immunotherapy in Children with Asthma and Rhinitis

“…However, in most countries of the world, AIT remains a niche treatment secondary to symptomatic drugs due to its cost, the long duration of treatment, poor compliance by patients and, in particular, concerns regarding safety and individual efficacy. There have been many observational studies on large samples [17,18,19]that recognize and deal with adverse reactions during treatment and evaluate safety in the long term after AIT [20]. There are few reports, however, on the development of methods for identifying AIT-responsive and nonresponsive endotypes and phenotypes to guide patient selection.…”

Anaphylaxis: the acute episode and beyond

“…However, in many immunisation clinics, infusion clinics, and allergen immunotherapy clinics, nurses are preauthorised to do this. 30 In community settings, adrenaline is often self injected through an autoinjector by the patient or injected by the parent, teacher, or other person responsible for the child. Delay in administration is associated with greater likelihood of biphasic and protracted anaphylaxis, and of death 23 24 ; in a UK series, only 14% of the patients who died from anaphylaxis received adrenaline before respiratory or cardiac arrest.…”