What is Urticaria (allergy/ hives) and how to identify it?

Urticaria is a transient erythematous swelling of the skin, associated with itching, which usually resolves within 24 hours. It is caused by degranulation of histamine containing cells (mast cells) in the superficial dermis. Hives often appears as a raised, itchy rash. The medical name for hives is “urticaria”, also call it welts, wheals, or nettle rash. Hives affects around 20% of people at some time in their lives. The issue can be chronic or acute. It is not possible to catch hives from another person. However, in some cases, hives occurs with a contagious infection.

How long does the individual lesion last?

<24 hours (Urticaria)

>24 hours (Urticarial Vasculitis)

How long has the condition been present?

<6 Weeks (Acute Urticaria)

>6 Weeks (Chronic Urticaria)