Management of Grade 2 Allergic Reactions

Introduction to Grade 2 Reactions

The American Academy of Allergy, Asthma, and Immunology recommends that Grade 2 reactions involve symptoms or signs affecting more than one organ system and represent moderate severity allergic reactions 1
Grade 2 reactions may include generalized pruritus, urticaria, flushing, or sensation of heat, angioedema, mild asthma symptoms, rhinitis, throat clearing, or conjunctival symptoms, nausea, metallic taste, or headache 1

For a Grade 2 allergic reaction in an inpatient setting, the American College of Allergy, Asthma, and Immunology recommends stopping or slowing the infusion if drug-related, administering H1 antihistamines and H2 antihistamines, providing symptomatic treatment including bronchodilators if needed, and closely monitoring for progression to Grade 3 or higher severity that would require immediate epinephrine 1, 2
The European Academy of Allergy and Clinical Immunology suggests that if infusion-related, stop or significantly slow the infusion rate immediately 2
The American Academy of Allergy, Asthma, and Immunology recommends removing or discontinuing the offending agent if identifiable 3

The American Academy of Allergy, Asthma, and Immunology recommends administering H1 antihistamine (diphenhydramine) at a dose of 1-2 mg/kg per dose IV or oral, with a maximum dose of 50 mg 3, 4
The American College of Gastroenterology suggests administering H2 antihistamine (ranitidine) at a dose of 1-2 mg/kg per dose, with a maximum dose of 75-150 mg IV or oral 3, 4
The American Thoracic Society recommends albuterol administration via MDI (4-8 puffs for children, 8 puffs for adults) or nebulized solution (1.5 mL for children, 3 mL for adults), administered every 20 minutes or continuously as needed 3

The American Academy of Allergy, Asthma, and Immunology recommends considering corticosteroids (methylprednisolone or prednisone) at a dose of 1 mg/kg, with a maximum of 60-80 mg, to prevent biphasic or protracted reactions 3, 4
The British Society of Allergy and Clinical Immunology suggests observing patients in a monitored area for a minimum of 6 hours from the onset of the reaction 6
The American College of Allergy, Asthma, and Immunology recommends continuously assessing for progression to Grade 3 or 4 severity and monitoring vital signs, respiratory status, and skin findings 1, 2, 6

The American Academy of Allergy, Asthma, and Immunology recommends administering epinephrine immediately if lower respiratory symptoms do not respond to inhaled bronchodilators, or if there is laryngeal edema, hypotension, or respiratory failure 1
The American Heart Association suggests epinephrine dosing at 0.01 mg/kg of 1:1,000 solution IM, with a maximum of 0.5 mg per dose 5

The American Academy of Allergy, Asthma, and Immunology recommends continuing adjunctive medications, including diphenhydramine every 6 hours for 2-3 days, H2 antihistamine twice daily for 2-3 days, and prednisone daily for 2-3 days 3, 4
The American College of Allergy, Asthma, and Immunology suggests prescribing an epinephrine auto-injector with proper training for any patient at risk of recurrent reactions 3, 4