Almost everyone has had itchy blisters similar to those that appear after touching the nettle leaves at least once in their lifetime.
However, when there are pink or porcelain-white itchy blisters on a flat surface, not caused by contact with a common herb, which is a nettle - we have probably to do so with the so-called urticaria based on skin allergy.
What is the course of urticaria?
This common skin disease can be acute or chronic. It is also one of the most common and troublesome ailments both for patients and for doctors. The urticaria-induced blisters are characterized by high dynamics, i.e. the speed of formation, and the resolution of changes, sometimes after several hours, without leaving any traces. Although they can last up to several weeks, and the disease that recurrently develops in the form of urticaria may last for years.
What course has the so-called acute urticaria and what causes it?
Acute urticaria lasts from several hours to 6 weeks. Its cause may be an allergic base associated with IgE antibodies (ie the mechanism of immunological confusion, as a result of which the allergen is recognized as a harmful factor - a germ or a parasite). Allergens can be foods and inhalation allergens that reach the skin along with the blood (plant pollen, house dust, gases, smells, etc.). Non-allergic causes are: psychological basis or the action of direct histamine triggers - pseudoallergy, which in terms of symptoms may look like an allergy, but it is not. An example is a hypersensitive reaction to anti-inflammatory drugs - acetylsalicylic acid, naproxen, ibuprofen, etc. (so-called aspirin nettle). Relatively safe in this set of anti-inflammatory drugs is paracetamol.
What do we know about chronic urticaria? Who passes it? How long does it take?
About 15-20% of the population undergoes urticaria at least once in their lives, 75% of whom experience chronic or recurrent skin symptoms lasting at least 6 weeks. We say then that urticaria is chronic, because urticaria eruptions (wheals) appear periodically for several weeks, months, and even years.
Can we determine the cause of urticaria and avoid the allergen or substance that causes it?
Allergens and urticaria - it's a difficult compound to establish. In the case of acute urticaria, you can try to identify the allergen. This is helped by the repetitive characteristic time relationship between eating some food (usually a few hours) or taking the drug (the compound is often almost instantaneous) and the onset of blisters and itching. For example, it is relatively easy to identify urticaria after eating the first strawberries, strawberries, cherries or raspberries in the season. A bit harder, but it is also possible to establish a relationship between eating foods that we eat throughout the year - fish, nuts, bananas, eggs, chocolate etc. You can also detect contact allergens to the skin - masks, masks, etc. - because the skin reaction takes place sometimes after a few hours. It is much more difficult to detect inhalation-free, odorless allergens.
Which of the food allergens most often cause urticaria?
In children who suffer particularly from this disease, every third disclosed cause of urticaria was food. Among the foods responsible for urticaria, the most common allergen is milk protein and its products, cereal protein (gluten), soy protein, egg white, animal protein (fish). Citrus fruits, bananas and some berries occupy high places among allergens. Both in children and in adults the cause of urticaria may be parasites (eg human worm).
Why is cow's milk a frequent allergen?
About 30 proteins with strong allergen properties are found in cow's milk. These are mainly: beta-lactoglobulin, casein, alpha-lactalbumin, albumin and cow's globulins. The incidence of allergy to these proteins is set at 0.3-7.5%. children's population.
What fruits and vegetables most often cause allergies in infants?
The allergic fruits include: oranges, lemons, mandarins, grapefruit, bananas, strawberries, strawberries, raspberries, and vegetables - tomatoes, celery, parsley. These fruits and vegetables should be avoided at least until the end of the first year of life.
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What other food substances can cause allergies?
Itchy blisters also appear in hypersensitive people after eating products to which preservatives (benzoic acid and its derivatives - benzoates) or artificial colors have been added. Foods that contain histamine alone - especially fish with tuna and mackerel, some hard cheeses as well as cabbage and spinach - may also be dangerous for food allergies.
However, when there are pink or porcelain-white itchy blisters on a flat surface, not caused by contact with a common herb, which is a nettle - we have probably to do so with the so-called urticaria based on skin allergy.
Do drugs cause urticaria?
Acute urticaria may also occur as a result of medication. The most dangerous is penicillin, but also penicillin-like compounds. As often, wheals appear on the skin after taking acetylsalicylic acid (aspirin) and other anti-inflammatory drugs that may or may not include acetylsalicylic acid or its derivatives (salicylates). Sensitization does not have to occur after a single use, and often only after prolonged use. So be careful when taking other popular non-steroidal anti-inflammatory drugs and analgesics, among others ibuprofen, naproxen, etc.
Treatment of urticaria
The drugs of choice are antihistamines. However, if the disease is rapid, with a fall in blood pressure or shortness of breath, parenteral corticosteroid preparations are administered. After the disappearance of violent symptoms, the patient is given antihistamines for several days.
Treatment of allergic disorders
Sometimes urticaria will disappear as a result of treatment, but the skin is still red, it itches a little and is strangely tense - why?
In addition to cells that are still "living" in the dermis - ie fibrocytes, lipocytes, and nerve cells - other cells called immune cells, e.g. macrophages and monocytes, settle in for a time. Although we have successfully used an antihistaminic drug and histamine blisters have disappeared - these effluent cells purifying the skin of everything unnecessary and harmful, they still "clean up" for some time. The inflow cells do not fit in such a tight area as the skin. As a result, it is tense, red and hard for some time. This is also because other allergic mediators are also involved in the allergic reaction, eg brykinin, which may last longer and cause pruritus.
Does allergic urticaria reduce the skin's resistance to other diseases?
Yes. A person suffering from allergic urticaria will probably be more likely to undergo bacterial skin diseases (boils, purulent abscesses, etc.), as well as viral infections of the skin (warts, herpes, etc.) or skin, nail or vaginal mycosis. This means for those people the need for increased personal hygiene. Although, on the other hand, increased activity of the immune system can sometimes help to fight infection.
What kind of research can we expect - by choosing an allergist with a request to determine the cause of urticaria?
First of all, we should write down before the visit, on a special sheet - all the foods and drinks we have consumed 48 hours before the appearance of wheals. We should also have a blood count, a stool test, etc. for the presence of parasites, tests with inhalation allergens, aspirin, food tests, determination of the level of immunoglogulin in blood, etc.
ed. Edward Ozga Michalski, MA
Consultation by prof. dr hab. med. Andrzej Danysz