Updated:

January 20, 2020

What Are Hives and What Causes Them?

 Hives, medically known as urticaria, are a collection of red, raised skin bumps that may be associated with an allergic reaction.

The bumps, rash, or welts associated with hives can vary in size, from the size of a pencil eraser to as big as dinner plates. They may cause itching, burning, or stinging sensations.

Who gets hives?

Many different people can experience hives at just about any point in their lives, depending on the cause. They can affect people of all ages, from infants to the elderly. 

Hives can also appear just about anywhere on the body. This can include the face, lips, ears, and even in the mouth or throat.

In most cases, hives only last from a few hours to a few days, and do not return. Other people, however, may have chronic hives that last weeks, months, or even years.

What causes hives?

When they are caused by allergies, hives occur because plasma in the blood reacts to the chemical histamine by leaking out into the skin. Histamine is a chemical released by blood-vessel cells in the skin in response to an allergen.

There are many different allergens that can cause the histamine release that triggers hives. Some of these allergens include:

●     Chemicals in certain foods

●     Insect bites or stings

●     Sunlight exposure

●     Certain medications

●     Infections, including the common cold or flu

●     Extreme temperatures or sudden temperature changes

●     Some plants, such as poison ivy

●     Common allergens, such as pet dander, dust mites, or pollen

Sometimes, however, hives may not have an obvious cause. Test results may come up negative, especially if the hives have become chronic (lasting for more than six weeks).

Can hives be dangerous?

Hives are not usually harmful or dangerous by themselves. Chronic hives alone do not make you more vulnerable to a sudden, serious allergic reaction (also known as anaphylaxis).

However, while hives themselves are not dangerous, they may accompany other symptoms that may be dangerous or indicate serious health issues.

If you or a loved one experiences any of these symptoms with hives, seek medical care immediately:

●     Throat tightness

●     Wheezing

●     Swollen tongue

How are hives treated?

Whether the hives are chronic or acute (that is, they occur suddenly or on a short-term basis), over-the-counter antihistamines can help prevent or manage symptoms. Antihistamines help block the effects of the histamine that can cause the rash and itching associated with hives.  

Antihistamines should be taken regularly to help prevent the hives from coming back, or as long as you are exposed to known causes. For example, if you know that pollen causes hives, you should take antihistamines for as long as pollen is present in the air. If you have hives in response to an animal, you should take antihistamines for as long as you are around that animal. 

When purchasing antihistamines for hives in stores or online, be sure to read labels and recommendations carefully. Some antihistamines cause drowsiness, and some are not suitable during pregnancy unless prescribed by a doctor.

For an emergency situation, such as difficulty breathing or swelling of the tongue, your healthcare provider may prescribe an epinephrine auto-injector, such as an EpiPen. 

If you know what causes your hives, managing your exposure and avoiding any triggers is the best way to keep them from coming back.

If hives persist, stronger prescription medications may be necessary. For example, the injectable biologic therapy Xolair is given once a month for conditions that include chronic hives with no known cause. This drug works by blocking immunoglobin E, a substance involved in allergic responses.

Some antibiotics, such as dapsone, may help reduce the redness and swelling from chronic hives. This type of antibiotic is used for a variety of skin conditions, including hives. It is important to visit a specialist for treatments like this.

Some people may find relief from hives from acupuncture, but experts warn that this method has not been thoroughly researched.

Should I see a specialist for hives?

If you struggle with chronic hives, it is important to talk to your healthcare provider. Chronic hives can lead to severe discomfort, stress, and possibly depression. These symptoms can not only further aggravate hives, but also lead to additional physical or mental health concerns.

Specialist treatment is usually not necessary for infrequent hives, especially if you know what triggers them, if they are not accompanied by more dangerous symptoms, and if the hives last only a few hours or days. In such cases, over-the-counter medication is usually enough to manage hives safely.

However, if your hives persist for 6-8 weeks or more, if you do not know the cause, or if over-the-counter medications do not help, it is a good idea to be evaluated for allergies or other internal medical issues.  

To determine the cause of hives, your specialist may recommend allergy skin testing or a blood test. The results will help determine the best approach for treating your hives and other allergy-related symptoms.

If you or your loved one is having trouble managing hives or other allergy symptoms, it may be time to consult a specialist. The allergy experts at Aspire Allergy and Sinus are ready to help you get answers and feel better. Find a location near you and contact us today to schedule your first appointment.

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