Treatment Corticosteroids
ÎImmediate-type reactions to corticosteroids are rare and may be either anaphylactic or anaphylactoid in nature. (C)
ÎMost reported reactions to corticosteroids involved intravenous methylprednisolone and hydrocortisone. Preservatives and diluents have also been implicated. (C)
Protamine
ÎSevere immediate reactions may occur in patients receiving protamine for reversal of heparinization. (C)
ÎDiabetic patients receiving protamine-containing insulin are at greatest risk of severe reactions due to intravenous protamine. (C)
Heparin
ÎHypersensitivity reactions to unfractionated heparin and low-molecular-weight heparin are uncommon and include thrombocytopenia, various cutaneous eruptions, hypereosinophilia, and anaphylaxis. (C)
Local Anesthetics
ÎMost adverse reactions to local anesthetics are not due to IgE- mediated mechanisms but are due to nonallergic factors that include vasovagal responses, anxiety, toxic reactions including dysrhythmias, and toxic or idiosyncratic reactions due to inadvertent intravenous epinephrine effects. (C)
ÎTo exclude the rare possibility of an IgE-mediated reaction to local anesthetics, perform skin testing and graded challenge in patients who present with a reaction history suggestive of possible IgE- mediated allergy to these drugs. (B)
Radiocontrast Media (RCM)
ÎAnaphylactoid reactions occur in approximately 1% to 3% of patients who receive ionic RCM and less than 0.5% of patients who receive nonionic RCM. (C)
ÎRisk factors for anaphylactoid reactions to RCM include female sex,
atopy, concomitant use of β-blocking drugs, and a history of previous reactions to RCM. (C)
ÎAlthough asthma is associated with an increased risk of a RCM reaction, specific sensitivity to seafood (which is mediated by IgE directed to proteins) does not further increase this risk. There is no evidence that sensitivity to iodine predisposes patients to RCM reactions. (C)
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