Subcutaneous allergen immunotherapy (SCIT) is an effective treatment for allergic
rhinitis, asthma and venom hypersensitivity and has the potential of producing serious
life-threatening anaphylaxis. Adverse reactions are generally classified into 2 categories:
local reactions, which can manifest as redness, pruritus, and swelling at the injection
site, and systemic reactions (SRs). SRs can range in severity from mild rhinitis to
fatal cardiopulmonary arrest. Early administration of epinephrine, which is the treatment
of choice to treat anaphylaxis, may prevent the progression of an SR to a more serious
life-threatening problem. Although there is little debate about using epinephrine
to treat a SCIT SR, there is a lack of consensus about when it should be first used.
A uniform classification system for grading SCIT SRs will be helpful in assessing
more accurately when epinephrine should be administered. The primary purpose of this
article is to discuss the proposed grading system for SCIT SRs.