Hives is an outbreak of swollen, red, bumpy rash that appear on the surface of the skin either as a result of the body's reaction to allergens or for other unknown reasons. The rash can be extremely itchy and can spread across the body. It may also burn or sting. The hives can appear anywhere on the body including ears, arms, hands, fingers, legs, feet or toes.
According to Mayo Clinic, hives vary in size and shape and may join together to form larger areas known as plaques. They typically last for few days and do not leave any long-lasting skin changes. About 20% of people are affected by hives at some time in their life.
Here's more on the types, causes, symptoms, diagnosis and treatment of the condition.
Hives: Types
Also known as urticaria, hives are not contagious. There are several types of hives as mentioned by the World Allergy Organisation:
Acute urticaria or hives lasting for less than 6 weeks. These may appear as a result of adverse allergic reaction to certain foods or medications. Insect bites and infections may also be responsible for acute urticaria. Hives occurs equally in males and females and are more common among children.
According to Mayo Clinic, chronic urticaria are hives that last for more than 6 weeks and unlike acute urticaria, causes are difficult to identify. In some cases, it may be due to an underlying disease like cancer, hepatitis, thyroid disease or infection. This is a more serious type and can spread to different areas of the body like lungs, gastrointestinal tract, muscles, etc
Dermatographic urticaria is a form of physical urticaria when hives occur as a result of scratching or firm stroking on the skin.
Hives: Causes
According to the US NIH, hives occur when the body reacts to an allergen and releases high levels of histamine and other chemical messengers into the skin. As a result, blood vessels in the affected area open up and start to leak. The resulting fluid in the tissue causes swelling and itchiness.
Many substances in the environment can trigger hives outbreak. Some common triggers include food such as wheat, nuts, eggs, strawberries, shellfish, food additives, etc. Other triggers as mentioned by NHS include:
Hives: Signs and Symptoms
According to Healthline, various signs and symptoms of hives may include raised, itchy bumps that are usually red or pink. A rash that appears often in several places and goes away in a matter of minutes or hours only to appear elsewhere.
These bumps are also called welts and can be of the same colour as the skin. It can be round-shaped, ring-shaped or in any random shape. It may change its size, colour and may spread to different parts.
Hives: Diagnosis
According to Mayo Clinic, the doctors may ask you a series of questions. The doctors will examine the bumps or rash if they are still present and take the medical history to identify the possible causes.
An allergy skin test may be performed to determine the substance to which you are allergic. The doctor may also order a few blood tests.
Hives: Treatment
According to the NHS, the goal of the treatment is to relieve symptoms while the condition resolves by itself. Antihistamines are usually prescribes to provide relief from symptoms. They are taken orally for several weeks and may include cetirizine or fexofenadine.
Chronic urticaria can be treated with an antihistamine or a combination of medications and if antihistamine doesn't provide relief, oral corticosteroid may be prescribed. Omalizumab and Xolair can also treat chronic urticaria. In several cases, home remedies may be effective as well.
It's important to consult your doctor before taking any medication.
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