Urticaria or hives is a common allergic skin condition characterized by transient red weals accompanied by itching. Urticaria – red weals on the skin can be flat or raised, of different sizes and shapes, merging into unusual shapes. Individual urticaria lasts for several hours, recedes spontaneously, and new outbreaks appear suddenly. Stronger swelling of the tissue occurs on the contacts of skin and mucous membrane (eyelids, lips, genitourinary area), and is more painful than itchy, occasionally causing respiratory problems.
What causes hives?
Hives occur when your body comes into a contact with an allergen, causing an allergic reaction in the blood vessels, their dilatation, leakage of plasma and formation of itchy urticaria. The most common triggers of urticaria are drugs, bacterial infections, certain foods, pollen, parasites and insect poisons.
Urticaria in children is often caused by food allergens, like hazelnuts, almonds, walnuts, peanuts, chocolate, honey, egg yolks and berries. Foods should be introduced into a childrens’ diet gradually, with intervals of 7 days, in order to notice an allergic reaction to a certain food. If some food causes respiratory problems, it is not advisable to take it again. In children, intestinal parasites can be a common cause of hives.
In adults, the most common causes of urticaria are antibiotics, nonsteroidal antirheumatic drugs, aspirin, azo dyes and benzoates, so they should be avoided. In almost 70% of examined urticaria cases causes were not found.
How long does urticaria last?
Urticariais an allergic disorder that can last for days or weeks. By removing the causative allergen, the lesions stop developing. If the hives do not recede for more than 6 weeks, more detailed tests are needed. Then we talk about chronic urticaria, which is mostly associated with vasculitis or systemic autoimmune diseases.
How are hives treated?
Antihistamines are used to treat hives, while avoiding recognized causative agents. Bacteriological tests, blood analysis and other tests are performed only after 6 weeks of hives development. When a particular allergen is suspected, specific IgE antibodies to that allergen may be tested. In people who, in addition to urticaria, also have digestive problems, it is advisable to perform a test for Helicobacter pylori infection. Sedative and non-sedative antihistamines are used for treatment, but should not taken during allergy tests.
Special forms of hives
Dermographic urticaria is the most common form of physical urticaria. Urticaria on the skin occurs at sites of trauma, friction with clothing, or scratching, with the creation of red and itchy patches that recede in 15 to 30 minutes. People with atopic disorders have this form of urticaria, and the treatment is not necessary.
Urticaria caused by cold
After direct contact of the skin and mucous membrane with cold drinks, cold air or cold wind, urticaria and redness occur, accompanied by moderate itching. It is advisable to avoid exposure to cold, and especially it is forbidden to jump into cold water, because of the risk of developing generalized urticaria.
Urticaria can develop a few minutes after exposure to the first spring sun. Urticaria recedes in 1 hour, and the redness can last up to 3 hours. There are no lesions on the face and hands.
Contact urticaria develops after skin contact with allergens, leading to redness and hives. Allergens are often foods, plants, drugs or additives in cosmetics. Contact urticaria is more often present in bakers, hairdressers, housewives, cooks.
Cholinergic urticaria occurs after a rise in body temperature, which is caused by physical exertion, emotional stress or the intake of hot, spicy food and alcohol. Small, pale papules appear on the skin, surrounded by red band, accompanied by itching. They most often appear on the trunk, arms, thighs and last for 30 to 60 minutes. It is advisable to avoid warming up, excessive physical activity and tension, and then treatment is not necessary.
Pigmented urticaria is associated with mastocytosis. The appearance of urticaria is characteristic, occurring after scratching brown and red spots on the skin.