The kid`s health... Can there be anything more important than that? - Nothing. So, every mom tends to be overconcerned about each small sign that might seem not normal. Some four or five years ago when my elder daughter was sick there appeared lots of pink spots all over her body. The first idea that came to my mind was that it was chickenpox since the spots were quite a lot. I phoned our pediatrician who recommended watching the spots and the girl`s condition carefully within an hour. Very soon I realised I`d been wrong about Chickenpox, for the spots were too vast. I considered everything that had been happening earlier that day and found that an hour earlier I had given my daughter a new syrup against fever. Immediately I applied an antihistamine gel onto the large pink spots. By the time our pediatrician arrived the spots had nearly disappeared. I was explained that it was Urticaria.
Urticaria (from the Latin urtica, nettle, commonly referred to as hives) is a kind of skin rash notable for pale red, raised, itchy bumps. Hives are frequently caused by allergic reactions; however, there are many nonallergic causes. Most cases of hives lasting less than six weeks (acute urticaria) are the result of an allergic trigger. Chronic urticaria (hives lasting longer than six weeks) is rarely due to an allergy.
The majority of chronic hives cases have an unknown (idiopathic) cause. In perhaps as many as 30 to 40% of patients with chronic idiopathic urticaria, it is caused by an autoimmune reaction. Acute viral infection is another common cause of acute urticaria (viral exanthem). Less common causes of hives include friction, pressure, temperature extremes, exercise, and sunlight.
Wheals (raised areas surrounded by a red base) from urticaria can appear anywhere on the surface of the skin. Whether the trigger is allergic or not, a complex release of inflammatory mediators, including histamine from cutaneous mast cells, results in fluid leakage from superficial blood vessels. Wheals may be pinpoint in size, or several inches in diameter.
Angioedema is a related condition (also from allergic and nonallergic causes), though fluid leakage is from much deeper blood vessels. Individual hives that are painful, last more than 24 hours, or leave a bruise as they heal are more likely to be a more serious condition called urticarial vasculitis. Hives caused by stroking the skin (often linear in appearance) are due to a benign condition called dermatographic urticaria.
Acute urticaria is defined as the presence of evanescent wheals which completely resolve within six weeks. Acute urticaria becomes evident a few minutes after the person has been exposed to an allergen. The outbreak may last several weeks, but usually the hives are gone in six weeks. Typically, the hives are a reaction to food, but in about half the cases, the trigger is unknown. Common foods may be the cause, as well as bee or wasp stings, or skin contact with certain fragrances.
Chronic urticaria (ordinary urticaria) is defined as the presence of evanescent wheals which persist for greater than six weeks. Some of the more severe chronic cases have lasted more than 20 years. A survey indicated chronic urticaria lasted a year or more in more than 50% of sufferers and 20 years or more in 20% of them.
Acute and chronic urticaria are visually indistinguishable.
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