Treatment of Acute Urticaria

First-Line Treatment: Second-Generation Antihistamines

The American Academy of Allergy, Asthma, and Immunology recommends beginning immediately with a second-generation non-sedating H1 antihistamine as the cornerstone of acute urticaria management, with options including Cetirizine, Desloratadine, Fexofenadine, Levocetirizine, and Loratadine 1, 2
Patients should be offered at least two different antihistamine options, as individual responses and tolerance vary significantly between agents 1, 2
First-generation antihistamines, such as diphenhydramine, hydroxyzine, and chlorpheniramine, should be avoided as primary therapy due to significant sedation and potential to worsen outcomes in severe reactions 1

If standard dosing provides inadequate control within 24-48 hours, the antihistamine dose can be increased up to 4 times the standard dose when benefits outweigh risks, as recommended by the Journal of Allergy and Clinical Immunology 1, 2, 3

The British Association of Dermatologists recommends adding a short course of oral corticosteroids for moderate to severe acute urticaria, rather than waiting for antihistamine failure 4, 5
A short course of oral corticosteroids, such as prednisolone 50 mg daily for 3 days, can achieve complete remission in a significant proportion of patients, and should be restricted to short 3-10 day courses only due to cumulative dose- and time-dependent toxicity 4, 5

The American College of Allergy, Asthma, and Immunology recommends immediately administering intramuscular epinephrine 0.5 mL of 1:1000 solution (500 µg) into the anterolateral thigh for acute urticaria with signs of anaphylaxis, followed by antihistamines and corticosteroids as adjunctive therapy 1, 5

The American Academy of Allergy, Asthma, and Immunology recommends identifying and eliminating triggering factors immediately, including upper respiratory tract infections, analgesics, and NSAIDs, and avoiding aspirin, NSAIDs, and codeine in all patients until triggers are clarified 2, 5
Cooling antipruritic lotions, such as calamine or 1% menthol in aqueous cream, can be applied for symptomatic relief while waiting for pharmacotherapy to take effect 2, 5