Management of Acute Urticaria

Introduction

Acute urticaria is diagnosed by the presence of weals, rarely with associated angioedema, lasting less than 24 hours (but can recur). Isolated angioedema should be investigated by Allergy Services, Immunology or General Medicine. Dermatology allergy patch testing is NOT used to investigate urticaria. Severe urticaria rarely progresses to anaphylaxis.

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))
• Bacterial infection
• Viral infection (e.g. lower respiratory tract infection)
• Food 'allergy' (uncommon)

See figure 1 for image of acute urticaria.

Treatment options

Treatment of anaphylaxis - see GGC Management of Anaphylaxis.

• Antihistamines
  • Non-sedating: oral fexofenadine 180mg, loratadine 10mg or cetirizine 10mg once a day. These can be gradually increased to up to four times a day, if required (note off-label use).
  • Sedating: chlorphenamine 4mg orally as required; maximum of 24mg in 24 hours can be added if required.
• Topical menthol for cooling effect, apply when required.
• Prednisolone oral 20mg once a day for 7 days (prescribe concurrently with antihistamine regime).
• Avoid possible triggers e.g. opioids, ACEIs, NSAIDs.

Guideline updated: September 2022

Page updated: September 2022