Sep 5, 2011
Acute urticaria which may last from several hours to several days, often has an allergic nature. In contrast, chronic urticaria, which exists in the weeks and months, very rarely is an allergic reaction. Urticaria often cause food allergens and additives, and drugs (often in the form of pseudoallergy).
Hives can take many forms, but it is always characterized by a rash of blisters, which may merge with each other. The rash can appear on any parts of the body and accompanied by severe itching.
Special forms of urticaria
Angioedema. Process involving a person and is accompanied by swelling of the lips, eyelids ("slit eyes"), mucous membranes and other body parts. Itching is absent, there is a painful burning.
Angioedema is a life-threatening if the process extends to the mucous membranes of the mouth and pharynx. Swollen tongue and back of the throat block the airway and can lead to suffocation.
The causes of urticaria are:
* Food allergens (egg, fish, nuts, fruits);
* Drugs (penicillins, hormonal, sulfonamides);
* Air allergens (pollen, hair, dust);
* Insect bites (bees, wasps);
* Infection (infectious mononucleosis, hepatitis B).
In contrast, allergic urticaria is one that is caused by physical factors: the sun, cold, atmospheric pressure.