HivesHives (urticaria) is a skin rash characterized by itchy wheals. The wheals vary in size and range from small, white bumps to large wheals that spread over entire skin regions.
Hives often appear only for a short time and then disappear again © iStock.com/Catherine Yeulet
It is estimated that about one in four people suffer from hives at least once in their life. The skin disease affects all age groups worldwide; only between the 30. and 50. only between the ages of 30 and 30 can a slightly higher incidence be observed than in other age groups.
How hives develop?
The typical wheals of hives are caused by water. Water is squeezed out of the blood vessels that lie under the skin into the upper layer of the skin. The water is also the reason why the hives are whitish in color.
What causes hives?
The actual trigger of hives is the messenger substance histamine. The histamine in the skin is stored in the mast cells. If the mast cells are irritated, more histamine is released at certain sites, resulting in the white, itchy wheals typical of hives. Irritation of the mast cells can have various causes.
The most common trigger of allergic urticaria is food, especially fish and shellfish, and legumes. Medications can also trigger an allergic reaction, which manifests itself in the form of hives. It does not matter whether the medication has been well tolerated up to now; drug-induced hives can occur at any time. The active ingredient acetylsalicylic acid is at least one of the triggers in about one-fifth of all cases of chronic hives.
Physically induced urticaria is triggered by stimuli that act directly on the skin: it results from prere, heat, cold or light. The most common physical urticaria is urticaria factitia: in this case, the hives develop after prere friction, such as brushing along the skin with an object.
Another common form is cholinergic urticaria. It is also called exertional urticaria and occurs with physical exertion, stress, sweating, or emotional arousal.
Unexplained (idiopathic) hives
In a number of cases of hives, the cause remains unclear. Infections, fungi, gastrointestinal diseases and thyroid disorders are discussed as triggers.
How hives manifest themselves?
The name urticaria is from "Urtica", derived from the Latin word for stinging nettle. There is an obvious reason for this: the symptoms of hives – itchy wheals on the skin – are similar to those after a "burn" With nettles. The wheals themselves are usually whitish, while the surrounding skin is reddish in color. But it also happens that the hives take on other colors, for example red. Itching is an important indicator of hives. Basically, a distinction is made between acute. Chronic hives. In acute urticaria, symptoms occur for less than six weeks. Chronic urticaria lasts correspondingly longer than six weeks.
Angioedema often occurs in addition to hives. Severe swellings appear particularly often on the face. Angioedema, in contrast to hives, itches only slightly or not at all and is not white in color.
Fever In the case of hives, can give an indication of the causative disease. If it occurs, a pediatrician should be consulted.
How hives are diagnosed?
After a discussion about the history of the disease with the doctor (preferably with a dermatologist), the wheals are examined. As a rule, hives are already diagnosed on the basis of their visual appearance.
If the hives do not heal on their own, it is first useful to keep a diary in which the period of occurrence of the hives, duration, frequency and any changes are recorded. This may provide clues to the cause of the hives.
The diagnosis is supplemented by various physical tests, such as the skin reaction to cold, heat and prere. It is also advisable to have an allergy test. Only in unclear or severe cases laboratory tests like blood and urine examination and the test for autoantibodies (autologous serum test) are concluded.
How to treat hives?
Since hives are not a disease in their own right but a symptom, the cause is treated. Treatment is then based on the causative disease, for example the allergy or infection. Often urticaria can be treated by avoiding certain foods or medications.
If no cause for the hives can be identified after a period of about six weeks, treatment is carried out with antihistamines. Antihistamines work by blocking the histamine docking sites in the tie. This is how the effect of histamine is weakened or prevented altogether. So at least the discomfort caused by the hives reduced.
In severe cases, cortisone can be used for a short time to treat hives.
Homeopathy for hives
For homeopathic treatment of hives, Urtica is usually recommended. Since homeopathy also treats according to the cause, the remedy should be selected after prior examination by a doctor experienced in homeopathy.
Is hives contagious?
No, hives are not contagious. It is rather a skin reaction due to allergy, hypersensitivity, overexertion or other, often psychosomatic causes. If an infection is the cause of the hives, the infection may be contagious, but not the hives themselves.
How does hives?
In most cases, hives will heal on their own: the spontaneous healing rate is 90 percent. In addition, there is also chronic hives, which usually lasts for several years. Here, a low-histamine diet is recommended. There is a particularly high amount of histamine in fermented foods or foods that are no longer completely fresh. Therefore it is advisable to avoid such foods. It is also advisable to eat unprocessed food as often as possible. Sweets and alcohol in particular are not suitable for a low-histamine diet.
Can you prevent hives?
Hives cannot be specifically prevented. However, it is possible to avoid the trigger factors if urticaria is already present. This is useful if you know the causes of hives. If it is idiopathic hives, i.e. urticaria with an unexplained cause, a low-histamine diet is recommended to prevent or reduce the formation of hives again.