Everything You Need To Know About Urticaria (Hives)
Everything you need to know about hives.
If you have ever experienced hives or know someone who has, you may have wondered what they are and why they occur. Urticaria or hives are a condition that approximately 20% of people will experience at some point for various reasons.
What Are Hives?
Hives are red, raised, itchy bumps that can occur anywhere on the body. They result from the body releasing histamine and other inflammatory molecules from mast cells in the skin.
They often resemble bug bites with a red or skin-colored raised center that is “blanchable”, meaning it turns white when pressure is applied; this indicates increased blood flow to the area.
Hives can be associated with angioedema, which is swelling deeper in the layers of the skin. Hives occur closer to the skin surface. Hives can occur with or without angioedema and vice versa.
Hives often occur without warning and typically “come and go”. They can appear somewhere on the body, disappear, and reappear somewhere else within 24 hours or less.
What’s The Cause?
Sometimes, the cause is apparent, like an allergy to medication or a food. But most of the time, a cause cannot be determined (idiopathic), especially if hives are “chronic” (occurring for six weeks or more).
Two types of hives are physical or inducible urticaria and spontaneous urticaria. Physical urticaria has physical causes like pressure, heat, sun, or cold. In chronic spontaneous urticaria, a cause is usually never identified but can be associated with thyroid disease, hormones, stress, and rarely cancers.
Common reasons for hives include:
Medications
Food
Infections
Physical pressure, such as tight clothing
Stress
Pollens
Pet Dander
Heat or cold
Water
When Should I See an Allergist?
If your hives have been occurring for over a month, you should see an allergist. An allergist is specially trained to obtain a relevant history and perform an exam to try and determine the cause of your symptoms.
Sometimes, if an obvious trigger to the hives is present, such as peanuts or shellfish, skin or blood testing may be performed at the appointment to determine if you are allergic.
If you are experiencing angioedema (swelling of the tissues) without hives, the allergist will order additional testing to determine if a deficiency in certain enzymes is causing the swelling. This is called hereditary angioedema and is different from chronic urticaria.
How is it Treated?
If a specific cause, such as a medication or food, is determined, the best treatment is avoidance.
If your hives are determined to be idiopathic (of unknown cause), the treatment is commonly antihistamines, which reduce the severity of the hives or prevent them from occurring entirely. Sometimes, if the hives are severe, your allergist will prescribe oral steroids like prednisone.
Although usually not life-threatening, hives can be extremely annoying and uncomfortable. It’s best to see an allergist who can help you through diagnosis and treatment.