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Hives are an allergic reaction to the skin, caused by insect bites, allergies or temperature variations, for example, which is manifested by reddish spots, which cause itching and swelling.
Usually, the symptoms of hives last up to 24 hours, disappearing without leaving marks or scars. However, the spots can reappear on other parts of the body, remaining for about 6 weeks, this type of urticaria being called chronic urticaria.
Hives can be controlled by avoiding exposure to the factors that trigger it and, in some cases, through the use of certain medications, such as anti-allergies.
Main causes
The causes of urticaria can be varied, but the most common include:
- Insect bites;
- Allergy to clothing fabric, pollen, latex, sweat, for example;
- Food coloring or preservatives;
- Excessive stress;
- Extreme heat or cold;
- Foods, such as peanuts, eggs, seafood;
- Infections, such as mononucleosis;
- Medicines;
- Cleaning products, toxic products or toxic plants;
- Diseases such as lupus or leukemia.
It is not always possible to find out the cause of the hives, however, the allergist doctor may do blood tests and allergy tests to try to better understand the symptoms and adjust the treatment.
What symptoms
The main symptoms of urticaria include the appearance of red spots that are swollen, itchy and, in more severe cases, swelling of the lips, eyes and throat and difficulty breathing, which requires immediate medical assistance.
These symptoms can be localized in a certain region or spread throughout the body, depending on the cause that is at its origin.
Types of hives
The main types of urticaria are acute urticaria and chronic urticaria, according to the duration of the allergy.
However, hives can be divided according to their cause, such as:
- Emotional or nervous urticaria: it is related to emotional factors, such as excessive stress or anxiety and, therefore, the symptoms are more intense during phases of greater tension. Learn more about this type of hives;
- Cholinergic urticaria: arises after an increase in body temperature, due to hot baths, eating hot foods or physical exercise, for example, and the symptoms last for about 90 minutes;
- Pigmented urticaria: caused by the excess of immune cells in the skin, known as mast cells, being more common in babies and children;
- Contact urticaria: arises after contact with allergenic substances, such as latex or resin, for example;
- Solar urticaria: caused by exposure to the sun and, therefore, the patient should avoid being exposed to the sun's rays.
In addition to these, there is also urticaria vasculitis, which is a rarer type of urticaria that causes inflammation of the veins, which can cause symptoms such as pain or burning in the affected area.
How the treatment is done
Urticaria treatment should be started by washing the affected area with soap and water, to eliminate an allergic substance, if possible.
In addition, in cases where it is not possible to identify the cause of the hives, the doctor may prescribe anti-allergic remedies, such as loratadine, cetirizine and hydroxyzine, for example, or topical or oral corticosteroid remedies, to relieve itching and swelling.
It is also possible to use cold compresses or soothing creams to reduce the symptoms of hives.
Learn more about how this problem is treated, according to the type of hives.