Urticaria

What is urticaria?

Urticaria is a skin condition which occurs quite frequently. Especially women are afflicted with urticaria. It is also known as hives or nettle rash as it appears as a reddening, very itchy skin irritation spread over various parts of the body. These wheals or bumps, similar to the skins' reaction after having contact with a nettle plant, usually go away by itself after less than 6 weeks.

Two types of nettle rash are known. The acute nettle rash and the chronic nettle rash. The acute nettle rash usually disappears after a couple of weeks, whereas the chronic can last up to several years. In this case the wheals could appear daily or in some cases only every couple of days. This very seldom form of nettle rash is quite difficult to treat. In only half the cases is the physician able to find the exact cause behind the chronic urticaria.

The body's own immune defence is activated in all cases of nettle rash. Hereby, so called mast cells recognise the bacteria of the skin infection and send out agents which activate the body's defence cells to help fight the bacteria. One such agent is histamine. Histamine enables the defence cells an easier access to the blood vessels in order to destroy the bacteria. This action also allows liquid to gather in the cells which is the cause for the appearance of the wheals. The itching is due to histamine as well. But it is not always the bacteria in the skin which makes the mast cells call histamine for help. Various reasons can set histamine free. In order to treat the wheals correctly, these reason have to be identified.

The various causes

The causes for the emergence of wheals and itching are numerous. Reactions to certain foods, drugs, infections or also causes of physical nature can be the reason.

Foodstuffs: e.g. mussels, fish, nuts and different kinds of preservatives. The reaction time differs, depending on when the food reaches the gastric system.

Drugs: available on prescription and non-prescription. Suspicious drugs are e.g. aspirin (acetylsalicylic acid), Beta-Blocker, ACE-inhibitors and histamine liberating drugs etc.

Infections: Even infections in other parts of the body can trigger the release of histamine in the skin. The meaning of the Helicobacter pylori infection in the gastro tract is currently discussed.

Physical factors: Coldness, warmth, sunlight but also psysical work, stress and applied pressure to the skin.

Dangers

Usually the nettle rash is not a dangerous condition besides having to bear the wheals and the irritating itching. But in some cases the mucous membrane in the nose-throat area is also affected by the swelling and therefore carries the risk of breathing difficulties. Furthermore can an over-release of histamine lead to an Anaphylactic Shock.