Why do hives appear on the skin? These are the surprising facts you might not know.

Hives, or known as urticaria, are itchy, raised welts that are found on the skin. They’re usually pink, red, or flesh colored on lighter skin and may be flesh colored or slightly lighter or darker than your skin tone on brown or black skin.

At times they sting or hurt. In the majority of cases, hives are caused by an allergic reaction to a medication or food or are a reaction to an irritant in the environment.

In many cases, hives are an acute (temporary) problem that may be alleviated with allergy medications. Most rashes go away on their own. However, chronic (ongoing) cases, as well as hives accompanied by a severe allergic reaction, are larger medical concerns.

What causes hives?

Hives are usually caused by an allergic reaction to something that you have encountered or swallowed. When you have an allergic reaction, your body begins to release histamines into your blood. Histamines are chemicals your body produces in an attempt to defend itself against infection and other outside intruders.

In some people, histamines can cause swelling, itching, and many of the symptoms that are experienced with hives. In terms of allergens, hives can be causedTrusted Source by factors such as pollen, medications, food, animal dander, and insect bites.

Hives might also be caused by circumstances besides allergies. It’s not uncommon for people to experience hives as the result of stress, tight clothes, exercise, illnesses, or infections.

It’s also possible to develop hives as the result of excessive exposure to hot or cold temperatures or from irritation due to excessive sweating. Because there are several potential triggers, many times the actual cause of hives can’t be determined.

Who is at risk?

People who are known to have allergies are more likely to get hives. You may also be at risk of developing hives if you’re taking medication or if you’re unknowingly exposed to things you may be allergic to, such as food or pollen. If you’re already ill with an infection or a health condition, you may be more vulnerable to developing hives.

Symptoms

Symptoms of chronic hives include:

– Batches of welts, called weals, that can arise anywhere on the body.
– Welts that might be red, purple or skin-colored, depending on your skin color.
– Welts that vary in size, change shape, and appear and fade repeatedly.
– Itchiness, also called pruritus, which can be intense.
– Painful swelling, called angioedema, around the eyes, cheeks or lips.
– Flares triggered by heat, exercise or stress.
– Symptoms that persist for more than six weeks and recur often and anytime, sometimes for months or years.

Finding relief: Treatment options

The first step in getting treatment is to figure out if you actually have hives. In most cases, a doctor will be able to determine if you have hives from a physical exam. Your skin will show signs of the welts that are linked with hives.

A doctor may also perform blood tests or skin tests to find out what may have caused your hives — especially if your hives were the result of an allergic reaction.

You may not need prescription treatment if you’re experiencing a mild case of hives not related to allergies or other health conditions. In these circumstances, a doctor might suggest that you find temporary relief by:

• taking antihistaminesTrusted Source, such as diphenhydramine (Benadryl) or – cetirizine (Zyrtec)
• avoiding irritating the area
• avoiding hot water, which may aggravate the hives
• taking a cool or lukewarm bath with colloidal oatmeal or baking soda

Seek emergency medical care

See a healthcare professional if you have severe hives or hives that last for more than a few days.

Chronic hives do not put you at sudden risk of a serious allergic reaction, called anaphylaxis. If you get hives as part of a severe allergic reaction, seek emergency care. Symptoms of anaphylaxis include dizziness, trouble breathing, and swelling of the tongue, lips, mouth or throat.