Overview

Hives, also called urticaria, are red, itchy, raised lumps or welts on your skin. They are pink or red, itchy rashes, which can occur as red dots on the skin or raised red bumps (wheals). 

These hives are more painful than they are itchy, can leave a bruising on your skin, and usually last longer than one day.

Urticaria -also known as hives, weals, welts, or stinging nettle rash - is a raised, itchy rash that appears on the skin. hives may be caused by factors like pollen, medications, foods, animal dander, and insect bites. 

What causes hives?

Many different substances in your environment can cause hives, including medications, foods, and physical agents. Medicines, like aspirin and antibiotics (especially penicillins and sulfas), are also common causes of hives.

Most commonly, Hives are associated with an allergic reaction that may make your skin itch for minutes. You can also be at risk for developing hives if you are taking medication, or are unknowingly exposed to things that you might be allergic to, like foods or pollen. 

Hives are caused by release of histamines and other mediators of inflammation (cytokines) by cells in the skin. In some people, hives are caused by physical triggers, including cold (such as cold air, water, or ice), heat, sunlight (solar), vibration, rubbing or scraping the skin (dermatographism), and delayed stress (such as after carrying a heavy bag). 

Who is at risk of having hives?

People with known allergies are most prone to developing hives. You also might be at risk for developing hives if you are taking medication, or if you are unknowingly exposed to things that you might be allergic to, like foods or pollen. If you are already sick with an infection or a medical condition, you might be more susceptible to developing hives.

What are the types of hives?

Acute hives  which last for six weeks or less, and can be caused by contact with an allergen or irritant, such as a food or touching a nettle.It is thought that about one out of six people will have a bout with acute hives at some time during their lives. Doctors do not exactly know why acute hives occur, but they can be associated with chronic medical conditions or autoimmune conditions. It may even happen with autoimmune conditions or systemic conditions, if the hives continue for an extended time.

When the hives appear on a majority of days for over six weeks, it is defined as chronic (continuous) urticaria, and additional medications may be needed.

Chronic hives may also be associated with thyroid disorders, other hormonal problems, or, very rarely, cancer. chronic hives which are marked by repeated itching, which may disrupt your way of life. When the cause of chronic hives is not known, the condition is called chronic spontaneous urticaria (CSU).  If a cause cannot be identified, even after detailed history and tests, the condition is called Chronic Idiopathic Urticaria.

In perhaps over 50% of people who have chronic hives for unknown reasons, they are caused by an autoimmune response.

Hive fever (or urticaria) is a common skin response to things such as an allergen (a substance that causes allergies).

In some cases, the person has both Hives and angioedema, a condition that causes swelling around the eyes, lips, hands, feet, or throat. Hives affect about 20% of the population at some point or another during their lives.

Cold-induced hives can result from cold water or exposure to air, and the heat of the body due to physical exertion can result in hives caused by physical exertion.

What do hives look like?

Unfortunately, for some people, the histamines cause swelling, itchiness, and many symptoms experienced in hives. While hives and facial swelling may be unpleasant and cosmetically disconcerting, they are usually not dangerous.

Along with hives, some people experience swelling deep within the skin or the moist tissues lining their mouth/lips, eyelids, or other areas.

When hives are caused by allergy or sensitivities, the hives may have significant effects on the face, such as by causing swelling of the lips.

How are hives diagnosed?

A healthcare provider might put ice on your skin to see how it responds to cold, or put a sandbag or other heavy object against his or her hips to see if pressure causes the hives. 

Diagnostic tests--such as blood tests, allergy tests, and tests to rule out conditions that may be causing the hives, such as thyroid disease or hepatitis--may be done to determine the exact cause of chronic hives. Your allergist might want to conduct skin tests, blood tests, and urine tests to determine the cause of your hives. 

Treatment of hives at home

To relieve hives, you can take a cool bath or shower, wear loose-fitting clothing and apply cold compresses. An OTC hydrocortisone cream can relieve itching and swelling.

If hives do not go away with treatment, a dermatologist (dermatologist) can be referred.

Takeaway

In most cases, hives are caused by allergic reactions to medications or foods, or reactions to stimulants in the environment.

If the hives are associated with a high fever, bruising, bleeding from the skin, purple bumps lasting several days, or aching joints, an urgent medical evaluation should be scheduled. 

Your healthcare provider can also do blood tests or skin tests to identify what might be causing the hives - particularly if they are a result of an allergic reaction. 

DISCLAIMER   

Tips and suggestions mentioned in the article are for general information purposes only and should not be construed as professional medical advice.