Have you ever been stung by a bee or wasp or bitten by a mosquito and developed an itchy, red, spongy, raised, flat bump? If  so, then you have experienced an "urticaria or hives." 

Urticaria (hives) is an outbreak of red bumps or patches called wheals that appear on the skin that are produced by the presence of histamine and brought on by a trigger.  The most likely causes of acute (sudden) hives is an allergy to pets, latex or foods, such as shellfish, eggs, soy, nuts, wheat or milk. Also quite common are insect bites or stings as well as medication allergy, such as antibiotics, ACE inhibitors, and aspirin.  In children, viral infections such as a cold can also trigger acute hives.  Some other triggers of hives are sudden temperature change, emotional stress, and even pressure on the skin.  

Episodes of hives can last from  48 hours up to six weeks and may come and go. However, if the wheals persist longer, chronic hives may be the case.  For In these cases, hives will eventually disappear on their own, with or without treatment, 50% of the time clearing within three to twelve months.  However, 40% of cases of hives can last one to five years, while up to 1.5% of these patients may experience hives for more than twenty years.

Triggers of most chronic hives are most often difficult to identify.  Interesting enough, a high percent of patients with chronic hives have auto-antibodies (antibodies against your own body tissues or cells) in their serum, which may contribute to histamine release  and hive formation.  This may be the reason why some patients with chronic hives respond very well to immunosuppressive agents.

Initially, avoiding aggravating factors, whether it may be a new medication, food, pets, as well as extreme cold or hot temperatures is wise.  Pay close attention to spices and preservatives such as sodium benzoate and food colorings such as tetrazine and consult your physician if you were started on new medication. 

Most of time, high doses of first generation antihistamine such as Benadryl, Atarax, may be necessary to control the itching and hives.  Because of their association with drowsiness, first generation antihistamines are best used at night.  Second generation antihistamines such as Clarinex, Allegra, and Zyrtec causing less drowsiness can be used and are very effective for maintenance treatment during the day.