In spontaneous hives, typical symptoms such as itching, wheals, and swelling of the skin occur suddenly and without an initially identifiable trigger. Depending on the duration of the rash, a distinction is made between acute and chronic hives: While acute hives usually subside after two weeks at the latest – but often after a few hours – the condition is referred to as chronic hives if the symptoms persist for longer than six weeks. Often, no cause for the symptoms can be found in chronic hives.
Physical hives
Physical hives are triggered by external stimuli such as pressure, cold, light, friction, or heat. In total, there are over 20 different subtypes. The following are the most common ones:
- Pressure hives: In this form of hives, pressure on certain areas of the body causes deep swelling. The swellings are particularly common on the back and the soles of the feet and palms of the hands.
- Cold hives: cold hives can be triggered by cold air, cold liquid, or cold objects. As with other forms of hives, there is swelling and wheals on the skin and mucous membranes. Symptoms occur either a few minutes after the cold stimulus or when the area warms up again. How large the cold stimulus must be to trigger the typical hives symptoms varies from person to person.
Patients suffering from cold hives should always carry an emergency passport in which the condition is noted. This is important, for example, for infusions, as affected persons may be administered only warmed.
- Light hives: This form of hives is usually triggered by UV-A rays, and in rare cases by UV-B rays. In those areas that have come into contact with the rays, hives form a short time later. However, the light hives is relatively rare.
- Friction hives: about two to four percent of Germans suffer from friction hives – the most common form of physical hives. The disease is triggered by friction on the skin. The typical hives symptoms can be caused, for example, by the rubbing of backpack straps, but also already by rubbing a T-shirt.
- Heat hives: In heat hives, the typical symptoms occur only in those areas that have come into direct contact with the heat source. Like light hives, heat hives are extremely rare.
Cholinergic hives
Cholinergic hives is the most common special form of hives. It is triggered by an increase in body temperature and occurs particularly in young adults. However, cholinergic hives are rarely treated because the symptoms that occur are usually mild. On average, this form of hives lasts between two and ten years before it finally disappears.
The trigger of cholinergic hives is an increase in body temperature. This can be caused, for example, by sports, spicy food, alcohol, fever, hot water or emotional stress. The first wheals may already appear during the rise in temperature. Usually they regress quickly, only in rare cases they persist for more than three hours.
Contact hives
Contact urticaria occurs only at the site that has come into direct contact with the trigger. Triggers can be a wide variety of substances: contact urticaria, for example, is often triggered by latex – especially occupational groups that often wear latex gloves are affected. But contact urticaria is also not a rare phenomenon in the kitchen: Here, the typical symptoms arise from contact with raw food, for example, when peeling potatoes or processing fish.
In the treatment of contact urticaria, it is particularly important to find the trigger of the symptoms. This must then be avoided in the future if possible. If this is not possible, antihistamines can be taken to suppress the unpleasant symptoms.
