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 (referrals directed to Glasgow) 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 images of acute urticaria.

Treatment options

Treatment of anaphylaxis - see Management of Anaphylaxis.

  • Antihistamines
    • Non-sedating: loratadine 10mg, cetirizine 10mg or oral fexofenadine 180mg 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.
  • If severe, consider prednisolone oral 20mg once a day for 7 days (prescribe concurrently with antihistamine regime).
  • Avoid possible triggers e.g. opioids, ACEIs, NSAIDs.
  • Also, refer to the British Association of Dermatologists website. N.B. Initial treatment of urticaria can be managed by primary care with outpatient referral to secondary care, if required.
Guideline reviewed October 2023
Page updated November 2023



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