If urticarial symptoms—redness, hives, and itching—persist much longer than 6 weeks, it is called chronic spontaneous urticaria. Discomfort can persist for several months or years, sometimes even for decades. Angioedema can also occur, especially in the facial area or on the hands and feet, and in the genital area. Now it is time to investigate the causes more thoroughly, and in this connection the doctor and patient need not adhere slavishly to the six-week limit. It depends not least on the severity of the discomfort.

Urticarial discomfort is always basically caused by the activation of mast cells. Therefore, discomfort can occur anywhere in the body where mast cells are present. Mast cells are found mainly in the skin and the mucous membranes of the respiratory and gastrointestinal tract. The activation of mast cells in the mucous membranes of the respiratory tract can lead to dysphagia and dyspnea, while the activation of mast cells in the gastrointestinal tract may cause abdominal pain, nausea, and diarrhea. Many patients also report indisposition, fatigue, headache, and joint pain that may occur during a severe urticaria attack.


Among the identified causes of such chronic spontaneous urticaria, in connection with which hives/angioedema may occur daily, weekly, or less frequently, are chronic infections or inflammatory processes (such as Helicobacter pylori), non-allergic hypersensitivity reactions to foods, food additives, and drugs (pseudo-allergies) and autoreactivity including autoimmune reactions (reactions caused by autoantibodies). That is, the body\’s immune system provides antibodies (immunoglobulins) against its own proteins. These are attacked by the defensive antibodies as if these antibodies were dealing with dangerous intruders such as bacteria. The body, as it were, fights itself. Therefore, we call such defense antibodies against “oneself” autoantibodies.


The search for the trigger (or triggers) is often detective work. The elimination of the underlying cause must be the goal of treatment of chronic urticaria. In the case of infection urticaria, then, the infection should be eliminated, and in the case of intolerance urticaria-inducing substances should be avoided. If such a treatment approach is not possible or not successful, a symptomatic treatment is used (see Therapy graphic in the section Therapy of Urticaria).

The pragmatic approach is therefore to maintain a symptom diary and to watch closely: Where do the wheals/angioedema occur? What time of day? In connection with certain activities, such as when showering or during walks in the winter? Is there a connection with work time and leisure time or with certain foods, activities, hobbies or diseases?

Where foods or food additives are suspected as the cause, a three-week elimination diet may be helpful. One can start, for example, with tap water, black tea, rusks and then continue with potatoes and rice etc.: if the symptoms disappear in this time, new foods can be gradually introduced until one comes across those that trigger an urticaria attack.