urticaria
URTICARIA
Treatment Guideline Chart
Urticaria is characterized by sudden appearance of wheals and/or angioedema.
The intensity of the pruritus varies but may be severe enough to disrupt sleep, work or school.
It is classified acute if the urticaria has been present for <6 weeks and chronic if >6 weeks. A specific cause is more likely to be identified in acute cases.
It can be triggered by immunological or nonimmunological mechanism.

Urticaria Signs and Symptoms

Introduction

  • Urticaria usually affects the epidermis and upper layer of the dermis
  • It is mediated by mast cells which cause the release of multiple vasodilatory mediators locally, including histamine
  • Characterized by sudden appearance of wheals (hives) and/or angioedema
    • Wheals in urticaria are characterized by variable size surrounded by erythema, pruritis or burning sensation, and transient appearance (skin returns to normal within 30 minutes to 24 hours)
    • Angioedema in urticaria features sudden prolonged swelling of the lower dermis and subcutis or mucous membranes, produces pain or discomfort, and has slower resolution compared to wheals (up to 72 hours)
  • Intensity of pruritus varies but may be severe enough to disrupt sleep, work or school
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