Urticaria

Avoiding the triggers

The first thing that should be done - with the help of the dermatologist - is to try to determine the trigger. If this substance or stimulus is known, it can be avoided in the future. However, particularly acute urticaria frequently fades away before the triggering agent has been found. Often, infections play a role here as triggers, as do drugs such as the painkiller acetyl salicylic acid. Suspect, non-vital drugs should be stopped after consultation with the doctor to find out whether they are possible triggers.

The search for the trigger of chronic urticaria is more difficult. Primarily food and additives (colorants and preservatives) but also inflammations and infections in the upper gastro-intestinal tract have been identified as frequent triggers (e.g. stomach infections with the bacterium helicobacter pylori) can be considered.

The dermatologist/allergologist can carry out different measures to find the trigger. These include such things as laboratory or blood tests, mucuous membrane swabs and prick tests. With the prick test, various possible substances that trigger allergies are applied to the skin in the form of a solution. The wetted skin is scratched to enable the allergen to penetrate into the skin. If an allergy (oversensitivity) exists, a red swelling forms at the point concerned within a few minutes. It often takes a great deal of time until the triggering substance has been found beyond doubt, and in around half of the cases this is never the case. The 'diagnosis by exclusion' is then chronic-idiopathic urticaria.

Medicinal therapy

If it is not possible to find or avoid the trigger of urticaria (causal therapy), medication is used to suppress the symptoms of nettle rash. Drugs that suppress the release of histamine are of the greatest importance. These are called anti-histamines. In many cases, glucocorticoids are also prescribed in the short term. These are cortisone derivatives that combat the histamine reactions (e.g. redness of the skin).