Guiding Principles for the Recognition, Diagnosis, and Management of Infants with Anaphylaxis: An Expert Panel Consensus.

Infant anaphylaxis is an emerging risk, with food allergy the most common cause. Although the presentation of anaphylaxis involves the same systems as in older children and adults, there are real-world challenges to identifying symptoms of an allergic emergency in nonverbal children, as well as implementing optimal treatment. Recognition of anaphylaxis in infants can be challenging because allergic symptoms and certain normal infant behaviors may overlap. Intramuscular epinephrine is the treatment of choice for infants, as it is for older children and adults, and an epinephrine autoinjector approved by the Food and Drug Administration is now available for infants weighing between 7.5 and 15 kg. A panel of experts sought to develop guiding principles for the recognition, diagnosis, and management of anaphylaxis in infants, and provide a framework for the development of new guidelines and future research. Accordingly, anaphylaxis emergency action planning for infants was addressed by the panel. In considering formation of future infant anaphylaxis guidelines, health care providers should be aware of the needs to improve the recognition, diagnosis, and management of infants with anaphylaxis. Future research should identify and validate clinical criteria for the diagnosis of anaphylaxis in infants, as well as risk factors for the most severe reactions.

Seafood allergy and radiocontrast media: are physicians propagating a myth?

BACKGROUND: Recent surveys have indicated that the misconception that seafood allergy confers a disproportionately increased risk of adverse reactions to radiocontrast media remains pervasive among physicians and patients. One possible explanation for the persistence of this notion is that physicians responsible for radiocontrast administration are inadvertently contributing to its propagation. METHODS: An anonymous survey was sent to 231 faculty radiologist and interventional cardiologists at 6 Midwest academic medical centers. Two questions dealt directly with seafood allergy related to radiocontrast media administration, and 6 questions served as distracters. RESULTS: Sixty-nine percent of responders indicated that they inquire about a history of seafood allergy before radiocontrast media administration. Some 37.2% of responders replied that they would withhold radiocontrast media or recommend premedication on the basis of a history of seafood allergy. CONCLUSION: Even among faculty physicians at university medical centers, the notion of seafood allergy as a significant risk factor for adverse radiocontrast media reactions remains pervasive. Even if no action is taken on the basis of the answer, it seems probable that the act of inquiring about seafood allergy before radiocontrast media administration could lead patients and trainees to presume an inherent risk in patients who are seafood allergic, thus propagating the notion. Physician education with respect to seafood allergy and radiocontrast media administration is vital to halting the persistence of this misconception.

Histamine and antihistamines in anaphylaxis.

Anaphylaxis and anaphylactoid reactions are potentially fatal. These disorders are sometimes iatrogenic, and increase with increased exposure to drugs, synthetic substances, and medical procedures. Non-IgE-mediated anaphylactoid reactions are common in medical settings and are clinically indistinguishable from anaphylaxis. These reactions may be unrecognized if a rigid classic definition of anaphylaxis is used. Histamine is a primary mediator of anaphylaxis and signs and symptoms of anaphylaxis can be reproduced by histamine infusion. Histamine triggers a cascade of inflammatory mediators and modulates its own release. H1-antihistamines are adjunctive treatment therapy for acute anaphylaxis and anaphylactoid reactions, in which many mediators of inflammation are involved. Compared with epinephrine, the first-response medication of choice, antihistamines have a slow onset of action, and they cannot block events that occur subsequent to histamine binding to its receptors. Antihistamines are an important component of regimens for the prevention of anaphylaxis and anaphylactoid reactions in patients at risk, and may eventually have more widespread application in the perioperative setting. In some instances, such as with exercise-induced anaphylaxis and reactions to latex in sensitized individuals, prophylaxis regimens are not always effective. H2-antagonists are not detrimental in the therapy of anaphylaxis and many studies show a favorable outcome when combining H1- and H2-antagonist therapy for prophylaxis. They should be added to therapy at the discretion of the treating physician. Because of decreased antimuscarinic and central nervous system side effects, the newer antihistamines can be given in high doses, allowing more complete blockade of histamine receptors. These agents should lead to a reevaluation of the usefulness of antihistamines in both the treatment of acute anaphylaxis and in prophylactic regimens. The unavailability of parenterally administered second-generation H1-antagonists limits their usefulness in acute anaphylaxis and perioperative prophylaxis.