What are Hives?
What are Hives?

Hives also known as urticaria (ur-tih-KAR-e-uh) is a skin reaction that causes raised, red, itchy welts (wheals, or swellings) in sizes ranging from small spots to large blotches several inches in diameter. Individual welts appear and fade as the reaction runs its course. Angioedema is a related type of swelling that affects deeper layers in your skin, often around your eyes and lips.

In most cases, hives and angioedema are harmless and don't leave any lasting marks, even without treatment. The most common treatment for hives and angioedema is antihistamine medications. Serious angioedema can be life-threatening if swelling causes your throat or tongue to block your airway and leads to loss of consciousness.

Symptoms

Signs and symptoms of hives include:

Raised red or white welts (wheals, or swellings) of various sizes that can cover large areas of skin
Welts that resolve while new welts erupt, making it seem as if the condition "moves"
Itching, which may be severe
Rarely, burning or stinging in the affected area


Hives can be either acute or chronic. Acute hives last from less than one day up to six weeks. Chronic hives last more than six weeks sometimes for months to years.

Angioedema

Angioedema is a reaction similar to hives that affects deeper layers of your skin, the tissues underneath your skin, and the lining of your throat and intestines. Angioedema often appears around your eyes, cheeks or lips, but can also develop on your hands or feet, or genitals, or inside your throat or bowel. Angioedema and hives can occur separately or at the same time.

Signs and symptoms of angioedema include:

Large, thick, firm welts
Swelling of the skin
Pain or warmth in the affected areas
Difficulty breathing or swallowing, in severe cases


Hereditary angioedema is a rare but more serious inherited (genetic) condition that can cause sudden, severe and rapid swelling of your face, arms, legs, hands, feet, genitalia, digestive tract and airway. Signs and symptoms of hereditary angioedema include:

Sudden and severe swelling of the face, arms, legs, hands, feet, genitalia, digestive tract and airway
Abdominal cramping as a result of digestive tract swelling
Difficulty breathing due to swelling that obstructs your airway

Hereditary angioedema is not usually accompanied by hives.

Causes

Hives and angioedema are caused by triggers that produce a skin or tissue reaction by stimulating certain cells (mast cells) to release histamine and other chemicals into your bloodstream. Sometimes it's not possible to pinpoint the cause of hives and angioedema, especially when these conditions become chronic or recur.

Allergic reactions are one common trigger of acute hives and angioedema. Common allergens include:

Foods
Medications
Other allergens


Additional triggers include:

Environmental factors
Dermatographia (also known as dermographia)


Hives and angioedema also occasionally occur in response to blood transfusions, immune system disorders such as lupus, some types of cancer such as lymphoma, certain thyroid conditions, and infections
with bacteria or viruses such as hepatitis, HIV, cytomegalovirus or Epstein-Barr virus.

Hereditary angioedema is a rare inherited (genetic) form of the condition. It's related to low levels or abnormal functioning of certain blood proteins (C1 inhibitors) that play a role in regulating how your immune system functions.

Western Medicine Treatment

If your symptoms are mild, you may not need treatment. Many cases of hives and angioedema clear up on their own. But treatment can offer relief for intense itching, serious discomfort or symptoms that persist.The standard treatment for hives and angioedema is antihistamines, medications that reduce itching, swelling and other symptoms of histamine release. For severe hives or angioedema, doctors may also sometimes prescribe an oral corticosteroid drug such as prednisone which can help lessen swelling, redness and itching.

Adopted from mayoclinic.com