Dexamethasone in Allergic Reactions

Role of Corticosteroids in Allergic Reactions

The American Academy of Allergy, Asthma, and Immunology recommends epinephrine as the only first-line drug for anaphylaxis, administered immediately at 0.01 mg/kg intramuscularly in the anterolateral thigh 1
Antihistamines and corticosteroids, including dexamethasone, should never be considered substitutes for epinephrine in anaphylaxis treatment 1
Delayed use of epinephrine may be ineffective, and fatal outcomes are associated with delay or lack of epinephrine administration, with a strength of evidence classified as high 1

Dexamethasone should be administered only after adequate epinephrine and fluid resuscitation in severe allergic reactions, as recommended by the British Journal of Anaesthesia 2
The National Comprehensive Cancer Network recommends corticosteroids, including dexamethasone, as adjunctive therapy alongside oxygen, nebulized bronchodilators, antihistamines, and H2 blockers for severe allergic reactions 3, 4

The American Academy of Allergy, Asthma, and Immunology recommends assessing reaction severity and giving IM epinephrine immediately for life-threatening reactions, with a strength of evidence classified as high 1, 5
After epinephrine and initial stabilization, dexamethasone 4-8 mg IM/IV can be administered as adjunctive therapy, along with antihistamines and H2 blockers, as recommended by the National Comprehensive Cancer Network 3, 4
Patients should be monitored for biphasic reactions, with observation in a monitored area for a minimum of 6 hours or until stable and symptoms regressing, as recommended by the British Journal of Anaesthesia 2

For milder forms of allergic reactions, such as flushing, urticaria, or isolated mild angioedema, the American Academy of Allergy, Asthma, and Immunology recommends H1 and H2 antihistamines as primary treatment, with corticosteroids often recommended to prevent biphasic or protracted food-induced allergic reactions 6
Ongoing observation is warranted to ensure lack of progression to anaphylaxis, and if progression occurs, epinephrine should be administered immediately, as recommended by the American Academy of Allergy, Asthma, and Immunology 6
Systemic corticosteroids, such as dexamethasone, are often recommended to prevent biphasic or protracted allergic reactions due to their anti-inflammatory properties, with a strength of evidence supported by the Journal of Allergy and Clinical Immunology 6
After discharge, continuation of adjunctive treatment includes H1 antihistamine, H2 antihistamine, and corticosteroid, such as prednisone, as recommended by the American Academy of Allergy, Asthma, and Immunology 6

Recent evidence from the Society for Haematology and Oncology Teams advises against using steroids and/or antihistamines indiscriminately, recommending a more personalized approach tailored to the patient's symptoms, with a moderate strength of evidence 7
Repeated doses of steroids may further suppress immunity in immunocompromised patients, highlighting the need for a personalized approach, as recommended by the Society for Haematology and Oncology Teams 7