Purpose of review: As allergen sublingual immunotherapy becomes more widely used in Europe and draws the attention of physicians of the USA, it is important to compare and contrast the safety aspects of this therapy versus allergen subcutaneous immunotherapy.
Recent findings: There are reports of severe systemic reactions associated with sublingual immunotherapy, but no fatalities. There are various studies of systemic reactions, including those that result in death, associated with subcutaneous immunotherapy over its nearly 100-year worldwide experience. Local reactions are common to both forms of the treatment.
Summary: If both forms of therapy are equally effective, a cost (including safety aspects) -benefit analysis of sublingual immunotherapy versus subcutaneous immunotherapy is necessary to determine how best to incorporate both forms of specific immunotherapy into the management of allergic patients. Adherence to published guidelines will reduce the likelihood of adverse reactions.