What is hives?
Hives is an affliction with a wide variety of causes and courses, so it is difficult to define clearly. In the simplest terms, it can be defined as the presence of blisters, edema or both [1]. They are usually accompanied by itching or a burning sensation, which can be very troublesome, especially for children. Urticarial blisters are almost always reddened. Their characteristic feature is that they subside over time without leaving a trace. There is therefore no need to fear that disfiguring scars or ulcerations will remain after the symptoms have disappeared. Urticaria can be acute, i.e. lasting up to six weeks, or chronic, which manifests itself over a longer period of time [1,2].
What could be the causes of hives?
In this case, too, it is difficult to have one specific answer. There can be many causes, and they vary considerably. We divide them into three main groups: IgE-dependent causes, IgE-independent causes and causes completely unrelated to immune responses [3].
- IgE-dependent causes, as the name suggests, are related to class E antibodies (IgE). They underlie many common allergic reactions. Causes of urticaria in this group include inhalant allergens, food allergens, contact allergens, insect venoms, drugs and parasitic infections.
- IgE-independent causes include other reactions related to the immune system, but not to class E antibodies. These include autoimmune diseases, cryoglobulinaemia, infections, lymphoma and vasculitis.
- Non-immunological causes include elevated temperature, light, cold, water and others [3].
Where does hives come from?
In the simplest terms, hives result from the enhanced secretion of certain substances by mast cells in the body. These include, for example, histamine, which is also involved in allergic reactions. As a result of the secretion of these substances, the sensory nerves in the body become activated and the blood vessels dilate, causing redness. Plasma moves into the tissues, which we can observe externally as swelling [1].
In addition, hives sometimes result from another disease. It can also develop on the basis of various allergies, including food allergies [1]. In this case, molecular diagnostics can be extremely helpful. It makes it possible to determine precisely which allergen causes the unpleasant condition. Urticaria can also accompany autoimmune diseases, which include lupus and rheumatoid arthritis [2]. This sounds quite serious, but blisters on the skin also occur for less significant reasons. These include, for example, cold, light or other factors that are often difficult to identify [1].
How to deal with hives?
As always, when anything suspicious happens to our health, it is necessary to go to the doctor. A specialist, if possible, will try to find the cause of the condition, but unfortunately this is not always possible. Hives can be caused by a variety of factors, so pinpointing the right one is sometimes difficult.
If the cause of the disease can be identified, it is helpful to eliminate it from the patient’s environment if possible. Other options are to induce a tolerance in the patient to the agent to which he or she reacts with hives, or to prescribe appropriate medications. These are usually medications that reduce the body’s cells’ shedding of substances that cause hives, including histamine.
The allergologist, thanks to his knowledge and experience, will be able to implement the best course of action in the individual case. In case of any doubt, doctor will refer the patient for further examinations [1]. For this reason, even in the case of such a seemingly trivial condition as hives, self-medication is not the safest option.
Sylwia Gałązka
