Management of Acute Urticaria

Introduction

Acute urticaria is diagnosed by the presence of wheals, sometimes with associated angioedema, which lasts less than 24 hours (but can recur). Severe urticaria rarely progresses to anaphylaxis. Isolated angioedema without wheals should be investigated by Allergy Services, Immunology or General Medicine. Dermatology contact allergy testing is NOT used to investigate urticaria. 

Urticaria is mostly idiopathic but can also be triggered by:

• Drugs (e.g. aspirin/non-steroidal anti-inflammatory drugs (NSAIDs), opioids, angiotensin-converting enzyme inhibitors (ACEis))
• Infection (bacterial or viral)
• Food 'allergy' (uncommon)
• Physical stimuli (cold, pressure, friction, insect bites)

See Figure 1 for image of acute urticaria.

Treatment options

Treatment of anaphylaxis - see GGC Management of Anaphylaxis.

Treatment of urticaria and/or angioedema:

• Antihistamines
  • Non-sedating: oral fexofenadine 180mg, loratadine 10mg or cetirizine 10mg once a day. These can be increased to up to four times a day for symptom control (note off-label dosages for urticaria/angioedema).
  • Sedating: oral chlorphenamine 4mg every 4-6 hours as required; maximum of 24mg in 24 hours.
• Prednisolone oral 20mg once a day for 7 days (prescribe concurrently with antihistamine regime, consider need for gastrointestinal protection).
• Educate on avoiding possible triggers.
• Other considerations - e.g. review medications, treat concurrent infection, avoid physical triggers.

Guideline updated: February 2026

Page updated: July 2026