What are hives?
Hives are small areas of swelling that occur on the skin surface in random areas on the body. Other commonly known names for hives include welts or urticaria. The medical term for hives is wheals. Hives typically appear very suddenly and may be pink or red with a raised surface around the edges with associated itching. The vast majority of hives last for a few minutes to a few hours, but in some cases can last for days, despite treatment. Rarely, hives can progress to a more significant allergic reaction that includes swelling of the tongue and throat with difficulty breathing, in which case they are potentially life-threatening.
Are they caused by an allergic reaction or something else?
Allergic reactions are the primary cause of hives. It can be difficult to determine the specific inciting factors, but there are numerous stimuli that can cause them to appear. Food products, plant contact or ingested medications can cause hives. Physiologically, they occur when there is a large histamine release in the body from specialized blood cells called mast cells. The histamines cause fluid to leak around the blood vessels in the area they appear leading to the skin changes that can be easily seen.
How can you diagnose them and what is the best treatment?
The diagnosis of hives is visual. There are no specific diagnostic lab or x-ray tests required for the diagnosis. Since the physiologic cause of hives is due to histamine release, we use antihistamine medications in addition to topical or oral steroids as the mainstay of treatment. Applying a cool compress of the affected area can also be symptomatically helpful. If the hives are associated with tongue, lip or throat swelling and difficulty breathing you should seek medical attention immediately at a certified urgent care or emergency department. The vast majority of times, hives occur independent of these more significant symptoms. If you are able to identify the specific stimulus that may have caused hives, it should be eliminated. If you believe the hives are due to direct skin contact, the affected area should be washed to avoid continued exposure and ongoing symptoms.