Urticaria

Urticaria (also “hives”) is a disease characterized by the rapid appearance of hives and/or angioedema.

Hives are fast-moving rashes that tend to quickly change in size and move (disappear from one place and reappear in other places). They are raised, surrounded by redness, accompanied by a feeling of intense itching and sometimes burning. In most cases, they disappear within 24 hours, but they can appear again.

Angioedema is swelling in the deeper layers of the skin, usually localized on the eyelids, lips, genitals and extremities. Unlike nettles, here the feeling of itching is not so pronounced, in some cases it may even be absent, but at the expense of this, the defeat can sometimes be painful. It usually goes away after 8-72 hours. A particular risk exists when the swelling is localized in the area of the tongue, larynx or pharynx, where it can cause airway obstruction.

There are different types of urticaria, but in most cases it is the result of the activation of a type of cell in the skin called mast cells and the subsequent release of various substances (mediators) from them (eg histamine, prostaglandins, leukotrienes, cytokines…). It is these mediators that are responsible for the main symptoms of the disease.

The most common causes that lead to the activation of mast cells are different types of food, some drugs, insect bites, physical stimuli (exposure to the sun, cold, heat, mechanical effects…), physical activity, hidden infections and many others.