What are hives?

Hives are patches of skin that are typically itchy and appear puffy or raised compared to the surrounding skin. They may appear reddish in color on light-colored skin, but the color changes can be difficult to discern on darker skin. Hives can occur due to an allergy or when the body’s immune system is activated for another reason. In most cases, hives come and go within a few hours, but they can recur in some individuals. Some people who experience hives also develop a condition called angioedema, which is characterized by puffiness or swelling. Angioedema typically occurs in the face, eyelids, ears, mouth, hands, feet, or genitals.

Causes of hives

If you have recently developed hives for the first time, it is possible that you have a new allergy to something. Hives can be caused by allergies to a variety of substances, including medicines such as antibiotics or aspirin, foods such as eggs, nuts, fish, or shellfish, something that was touched, such as a plant, animal saliva, or latex, and insect stings. If your hives are caused by an allergy, it is important to avoid the allergen.

 Hives can also be caused or “triggered” by infections, such as those caused by viruses or bacteria. In this case, the hives occur because your immune system has been activated to fight the infection. Hives can appear days or weeks after an infection. In some cases, you may recall being recently ill, but hives can also occur with mild infections that may have gone unnoticed. Hives of this type usually only last a few days.

 There are also “physical” triggers for hives, such as exposure to cold air, water, or sun on the skin, exercise, having something press or vibrate against the skin, and changes in body temperature (such as when you cool down after a hot shower or a workout). However, it is often difficult to determine what has triggered hives.

Hives treatment

It is possible that you may not require treatment for hives, as they typically resolve on their own within a few days or weeks. However, if you are experiencing hives for the first time, it is recommended that you consult with your doctor or nurse to determine whether treatment is necessary. If so, the first step is to identify any triggers that may have caused the hives and avoid them.

Antihistamines are medications that can be used to alleviate itching and are the same medications that are typically used to treat allergies. If you have severe hives or your hives do not resolve, your doctor or nurse may recommend that you take steroids for a short period of time. Steroids are effective in reducing swelling and relieving itching, but they should not be taken for an extended period of time due to the risk of serious side effects.

When to seek emergency medical attention

If you experience sudden hives or swelling and also have any of the following symptoms, it is important to seek emergency medical attention immediately (call 911):

• Difficulty breathing, a hoarse voice, or wheezing (hearing a whistling sound when you breathe)

• Swelling, especially in the mouth or throat

• Throat tightness

• Feeling dizzy or nearly fainting