Hives (urticaria) are raised, red welts on your skin that last for a few hours before fading away without leaving marks. As new hives appear, they often itch but may burn or sting. Crops of new hives may appear as old ones are fading. Individual hives last less than 24 hours.
Hives may occur singularly or in groups on any part of the skin. They vary in size and form, from a pencil eraser to a dinner plate, and may spread or join together to form even larger irregular swellings.
There may be deep swellings (angioedema) around the eyes, lips or tongue.
Hives are very common. Approximately 20 percent of the population will have at least one episode in their lifetime. People who have other allergies or asthma are more likely to develop hives than those who do not.
Most episodes of hives resolve on their own in a few days to a few weeks. Occasionally, a person will have them for many months or years.
Hives may be uncomfortable, but they generally are harmless and disappear on their own. In most cases, the exact cause of hives cannot be identified.
Complications of Hives
In more serious cases — such as when swelling occurs inside your mouth or throat — complications can include:
Swelling in the throat can lead to life-threatening airway blockage
Loss of consciousness
Anaphylactic shock Anaphylactic shock (anaphylaxis) is a serious allergic reaction involving your heart or lungs. Your bronchial tubes narrow, it's difficult to breathe, and your blood pressure drops, causing dizziness and perhaps loss of consciousness or even death. Anaphylactic shock occurs rapidly, and requires immediate medical care.
If any of the following occur, call 911 immediately!
Tightness in the chest
Swelling of the tongue, lips, or face
What causes hives?
Hives and angioedema are usually the result of an allergic reaction, which triggers certain cells (mast cells) to release histamine and other chemicals into your bloodstream and skin.
Histamine causes the blood vessels to dilate and leak fluid into the surrounding tissue causing the skin to swell. This irritates nerve endings resulting in itching. In severe reactions, feelings of nausea, vomiting, and dizziness may be present.
Many things may cause hives, and very often a definite cause is never found.
Most common causes include:
Medications. Medications are the most common cause of hives.
Almost any medication, prescription, over-the-counter or herbal, may cause hives or angioedema.
Biggest culprits are
antibiotics (especially penicillin and sulfa drugs)
pain medications (such as aspirin and ibuprofen (Advil, Motrin, others)
blood pressure medications (like ACE inhibitors)
diuretics (“water pills”)
opiates (such as codeine)
other common medications are sedatives, tranquilizers, oral contraceptives, diet supplements, antacids, arthritis medication, vitamins, herbal supplements, eye and eardrops, laxatives, vaginal douches, or any other non-prescription items.
Foods. Many foods can cause problems in sensitive people.
The most common foods that cause urticaria are nuts, chocolate, shellfish, tomatoes, eggs, berries, especially strawberries, blue cheese and milk.
Fresh foods cause hives more often than cooked foods.
Food additives and preservatives, such as salicylates, benzoates and sulfites, may also cause hives.
Hives may appear within minutes to several hours after eating, depending upon the site within the digestive tract where the food is absorbed.
Infections. Many infections can cause urticaria.
Most common infections are infectious mononucleosis, urinary tract infections, colds, infected teeth or sinuses and hepatitis.
Physical Agents. Occasionally physical agents such as pressure, heat, sunlight, water, exercise, emotional stress, or cold may cause hives.
Other allergens. Other substances that can cause hives and angioedema include direct contact with pollen, animal dander, latex and insect stings.
Systemic Illness. Rarely, a number of illnesses can present with hives, including thyroid disease, autoimmune conditions and inherited diseases.
You may be at greater risk of hives and angioedema if you:
Have had hives or angioedema before
Have had other allergic reactions
Have a disorder associated with hives and angioedema, such as lupus, lymphoma or thyroid disease
Have a family history of hives, angioedema or hereditary angioedema
What do hives look like?
Raised, red or white welts (wheals, or swellings) of various sizes
A single welt or group of welts that can cover large areas of skin
Welts that resolve while new welts erupt, making it seem as if the condition "moves"
Burning or stinging in the affected area
Itching, which may be severe
Types of hives
There are several different types of hives, including:
Acute urticaria: Hives lasting less than six weeks. The most common causes are certain foods, medicines, or infections. Insect bites and internal disease may also be responsible.
Chronic urticaria and angioedema: Hives lasting more than six weeks. The cause of this type of hives is usually more difficult to identify than those causing acute urticaria. For most people with chronic urticaria, the cause is unknown.
Chronic urticaria and angioedema can affect other internal organs such as the lungs, muscles, and gastrointestinal tract. Symptoms include muscle soreness, shortness of breath, vomiting, and diarrhea.
Physical urticaria: Hives caused by direct physical stimulation of the skin -- for example, cold, heat, sun exposure, vibration, pressure, sweating, and exercise. The hives usually occur right where the skin was stimulated and rarely appear elsewhere. Most of the hives appear within one hour after exposure.
Dermatographism: Hives that form after firmly stroking or scratching the skin. These hives can also occur along with other forms of urticaria.
How Are Hives and Angioedema Diagnosed?
Your doctor can tell if you have hives by looking at your skin.
If you have a history of an allergy, then the diagnosis is even more obvious.
Occasionally, skin or blood tests are done to confirm that you had an allergic reaction, to test for the substance that caused the allergic response or to identify other possible causes of hives, such as systemic illnesses or infections.
How Are Hives and Angioedema Treated?
The best treatment for hives and angiodema is to identify and remove the trigger.
The mainstay of treatment for hives is the use of oral antihistamines
Chronic hives may be treated with antihistamines or a combination of medications. When antihistamines don't provide relief, oral corticosteroids may be prescribed.
For severe hive or angioedema outbreaks, an injection of epinephrine (adrenaline) or a cortisone medication may be needed.
People with severe reactions should wear a medical alert bracelet that describes their problem
What Should I Do When I Have a Hives Outbreak?
Avoid hot showers or baths, which can further aggravate your skin. A cool bath with oatmeal powder may relieve itching. Pat dry after bathing or showering. Vigorous rubbing of the skin, such as toweling off after a bath should be avoided.
Avoid wearing tightly fitted clothes or clothes made from rough fabrics such as wool
or coarse knits; as these may often worsen the itching of hives. Wear loose, smooth-textured cotton clothing.
Avoid heavy physical exertion and becoming overheated. If you stay relatively cool, the hives will often be less uncomfortable.
Avoid aspirin-containing compounds, ibuprofen and narcotics, which are all histamine-releasing agents. Check with your doctor prior to discontinuing any medications!
Eliminate use of alcoholic beverages since like aspirin, alcohol is a histamine releasing
chemical and often worsens hives.
Apply cool, wet compresses or ice packs in specific areas.
Take the antihistamine medications prescribed to you with great regularity during
the treatment period to produce maximum control of hives. It is usually not sufficient to take these medications only when the hives are present. They should be taken continuously according to the direction on the prescription, in order to maintain a constant high blood and tissue level. Most antihistamines can cause some drowsiness as a side-effect and you should be very careful if you drive or are involved in other activities which demand a high level of attention.
Summit Medical Group is proud to provide medical, surgical and cosmetic dermatology services to women and men in the Tri-State Area, New York and New Jersey, including the following counties and cities: Essex County, Morris County, Bergen County, Union County, Passaic County, Somerset County and Sussex County, NJ - Livingston, Millburn, Short Hills, West Orange, Berkley Heights, Caldwell, Cedar Grove, Cedar Knolls, Chatham, East Hanover, Englewood Cliffs, Essex Fells, Fair Lawn, Florham Park, Fort Lee, Glen Ridge, Jersey City, Kinnelon, Madison, Maplewood, Mendham, Montclair, Montvale, Morristown, New Providence, North Caldwell, Parsippany, Randolph, Roseland, South Orange, Springfield, Summit, Union, Verona, West Caldwell, Whippany and Westfield, NJ.
Disclaimer: The information on this Web site is solely for to educate patients. It is not intended to be medical advice and, therefore, should not be considered a substitute for consultation with a qualified medical professional. Communications to or from the Summit Medical Group Web site and any person will not be used to establish a relationship between a patient and doctor.