Other types of urticaria

In the group “other urticaria”, cholinergic urticaria and exercise induced urticaria as well as contact urticaria are collected. In contrast to that experienced in the case of spontaneous urticaria, the discomfort experienced in connection with these types of urticaria can be brought about deliberately, and the symptoms of these types of urticaria, in contrast to those of physical urticaria, occur independently of physical stimuli.

Cholinergic urticaria

Cholinergic urticaria is one of the more common types of urticaria. “Cholinergic” means that the neurotransmitter acetylcholine plays a role in connection with this form of urticaria. How exactly is currently not known; however, acetylcholine is released from nerves, and activates mast cells with a mechanism that is not fully understood. The most common trigger of cholinergic urticaria is physical (athletic) activity, but fever, stress, hot baths or showers, and even the consumption of too-spicy food or drinking liquor are also triggers. The wheals in cholinergic urticaria are typically smaller than those formed in the case of other types of urticaria and found in the \”welding areas\” (such as the underarms, back) of the concerned persons. Lesions in most cases appear within a few minutes after increasing the body temperature and with the onset of sweating, usually starting at the neck and upper body. After cooling the hives disappear without a trace within minutes to hours.

Cholinergic urticaria can be easily confused with the

  • Chronic stress-induced urticaria and
  • Exercise-induced urticaria/anaphylaxis

In the case of stress-induced chronic urticaria, physical exertion or a passive raising of body temperature does not lead to hives and itching.

In the case of exercise-induced urticaria/anaphylaxis, physical exertion, as in the case of cholinergic urticaria, leads to discomfort. In contrast to cholinergic urticaria, however, itching and hives are in this case caused solely by physical strain and not by passive heating (e.g. by hot baths).

Therapy

Unfortunately, the underlying causes of most cases of cholinergic urticaria are not known. Treatment of the symptoms (symptomatic therapy) is the only option. With antihistamines or ketotifen or danazol (which is closely related to the sex hormone androgen and should therefore be reserved for severe forms of the disease) or
Hardening: Patients can use the absolute refractory period by triggering an urticaria attack in a controlled manner (e.g. by means of exercise) and then are free of wheals for up to 24 hours. Controlled physical exertion several times daily can prevent the occurrence of pronounced attacks of hives.

Contact urticaria

Here the wheals arise wherever the skin comes into contact with a specific substance (or certain substances). Stinging nettles and jellyfish are classic examples. To be sure, this form of contact urticaria occurs in every healthy person who has the corresponding skin contact. A corresponding response to food or animal hair is less common. Latex, too—especially in health professions—can be the trigger of a contact urticaria. Rarely, cosmetics, or their ingredients (e.g. fragrances) are triggers.

Aquagenic urticaria

Yes, even water can cause hives. However, this is extremely rare. According to the literature, only 35 patients are known worldwide. And the reaction is most likely not really to water in its pure form, the chemical substance H2O, but to the minerals or unknown substances dissolved in the water. Due to the rarity of the disease more precise research is of course extremely difficult. If urticaria occurs while a person is showering or bathing, this should not be considered an indication of “aquagenic” urticaria: usually it is then a case of urticaria factitia (triggered by the mechanical stress of “soaping” or later drying).