Urticaria Day (UDAY) 2025

AAFA joins We CU, and The Mast Cell Disease Society (TMS) in recognizing Urticaria Day (UDAY) on October 1, 2025.

What is urticaria (hives)?

Hives (urticaria) are a type of swelling of the skin and are a common symptom of allergic reactions. Hives are itchy, raised bumps, called welts or wheals, on the skin. They can look like bug bites. Hives can be acute (lasting a short time) or chronic (lasting longer than 6 weeks).

• Acute hives are defined as hives lasting between a few minutes, hours, or days and no longer than 6 weeks. They can happen for a few reasons: allergic reaction, infection, or inflammation in the body.
• Contact hives are a form of acute hives. The hives occur at the site of contact with the allergen or irritating substance, up to 1 hour after the exposure. Contact hives can often go away if the area is washed off, and otherwise usually go away within a day.
• Chronic hives (chronic urticaria) occur almost daily and by definition have to last for more than 6 weeks. They are rarely caused by an allergic reaction to food or environmental trigger. The two common types of chronic hives are chronic spontaneous urticaria (CSU), which are hives that occur for no known reason, and chronic inducible urticaria (CIndU). CIndU are hives triggered by known physical factors such as cold, heat, pressure, friction, vibrations, exercising, sweating, and UV sunlight (rare).

About UDAY 2025:

• The theme of UDAY 2025 is Unmet Needs – The Path Forward for Urticaria.
• This awareness day aims to highlight the unmet needs of people living with urticaria and the vital role of clinical research in driving progress.
• UDAY 2025 is supported by the Urticaria Network E.V. (UNEV), the UCARE network, Global Allergy & Airways Patient Platform, and many organizations worldwide.